Electrolyte for a solid-state battery

ABSTRACT

Electrolyte for a solid-state battery includes a body having grains of inorganic material sintered to one another, where the grains include lithium. The body is thin, has little porosity by volume, and has high ionic conductivity.

PRIORITY

This Application is a continuation of International Patent ApplicationSerial No. PCT/US17/67376 filed on Dec. 19, 2017 which claims thepriority benefit of U.S. Application No. 62/437,157 filed Dec. 21, 2016;62/439,613 filed Dec. 28, 2016; 62/470,550 filed Mar. 13, 2017;62/439,609 filed Dec. 28, 2016; 62/526,806 filed Jun. 29, 2017;62/439,598 filed Dec. 28, 2016; 62/483,726 filed Apr. 10, 2017;62/484,106 filed Apr. 11, 2017; and 62/556,712 filed Sep. 11, 2017, eachof which is relied upon and hereby incorporated by reference herein inits entirety.

BACKGROUND

The disclosure relates generally to processes for sintering, such assintering green tape including polycrystalline ceramic grains or otherinorganic particles, bound in a binder, as well as continuous anddiscrete sintered articles, such as ceramic sheets, tapes or ceramicpieces made from such processes. The disclosure relates articles, suchas thin sheets, tapes, ribbons or pieces of ceramic or other inorganicmaterials that have many potential uses, such as serving as waveguides,when the ceramic is transmissive to light, serving as substrates thatmay be coated or laminated, and integrated in batteries and othercomponents, or used as or joined with a substrate such as to act as adielectric in an electronics package (e.g., LED package), or otherapplications. Various material properties, particularly of ceramicmaterials, such as high resistivity, low reactivity, low coefficient ofthermal expansion, etc. make such articles particularly useful in a widevariety of applications.

SUMMARY

Some aspects of the present disclosure relate to a tape separationsystem for sintering preparation. The tape separation system includes asource of tape material comprising a green tape and a carrier websupporting the green tape. The green tape comprising grains of inorganicmaterial in a binder. The tape separation system further includes apeeler for directing the carrier web in a rewind direction and directingthe green tape in a downstream processing direction that differs fromthe rewind direction, and a vacuum drum positioned and configured toreceive the tape material from the source and convey the tape materialto the peeler. The vacuum drum comprises holes for applying suction tothe carrier web to facilitate tensioning the carrier web, and tension,in force per cross-sectional area, in the carrier web is greater thantension in the green tape as the tape material is conveyed from thevacuum drum to the peeler, thereby mitigating deformation of the greentape during separation of the green tape from the carrier web.

Other aspects of the present disclosure relate to a system forprocessing tape for sintering preparation. The system includes a tapecomprising a green portion of the tape, the green portion having grainsof an inorganic material in an organic binder; and a binder burnoutstation comprising an active heater. The tape advances through thebinder burnout station such that the binder burnout station receives thegreen portion of the tape and chars or burns the organic binder as thegreen portion of the tape interfaces with heat from the heater, therebyforming a second portion of the tape prepared for sintering theinorganic material of the tape. In some embodiments, at an instant, thetape simultaneously extends to, through, and from the binder burnoutstation such that, at the instant, the tape includes the green portioncontinuously connected to the second portion, such as where the binderburnout station chars or burns at least most of the organic binder, interms of weight, from the green portion of the tape withoutsubstantially sintering the grains of the inorganic material. In someembodiments, system for processing tape for sintering preparationfurther includes an ultra-low tension dancer that includes light-weight,low-inertia rollers to redirect the tape without exerting significanttension such that tension in the second portion of the tape is less than500 grams-force per mm² of cross section, thereby reducing chances offracture of the second portion of the tape and facilitating longcontinuous lengths of the tape for sintering. In some embodiments,system for processing tape for sintering preparation blows and/or drawsgas over the tape as the tape advances through the binder burnoutstation, and the binder burnout station heats the tape above atemperature at which the organic binder would ignite without the gasblown and/or drawn over the tape, whereby the organic binder chars orburns but the tape does not catch fire.

Additional aspects of the present disclosure relate to a manufacturingline comprising the above system for processing tape, where the binderburnout station is a first station and the manufacturing line furthercomprises a second station spaced apart from the first station. Thesecond station at least partially sinters the inorganic material of thesecond portion of the tape to form a third portion of the tape, where,at an instant, the tape includes the green portion continuouslyconnected to the third portion by way of the second portion. Forexample, in some such embodiments, the third portion of the tape issubstantially more bendable than the second portion such that a minimumbend radius without fracture of the third portion is less than half thatof the second portion, and the green portion is substantially morebendable than the second portion such that a minimum bend radius withoutfracture of the green portion is less than half that of the secondportion. The manufacturing line may further include the tape separationsystem described above.

Some aspects of the present disclosure relate to a sintering systemcomprising a tape material comprising grains of inorganic material and asintering station. The sintering station includes an entrance, an exit,and a channel extending between the entrance and the exit. At aninstant, the tape material extends into the entrance of the sinteringstation, through the channel, and out of the exit. Heat within thechannel sinters the inorganic material such that the inorganic materialhas a first porosity at the entrance and a second porosity at the exitthat is less than the first porosity. Further, the wherein the tapematerial is positively tensioned as the tape material passes through thechannel of the sintering station, thereby mitigating warpage. In someembodiments, the tape material moves through the sintering station at aspeed of at least 1 inch per minute. In some embodiments, the channel ofthe sintering station is heated by at least two independently controlledheating elements, where the heating elements generate a temperatureprofile where the channel increases in temperature along the length ofthe channel in a direction from the entrance toward the exit of thesintering station, and where a sintering temperature in the channelexceeds 800° C. In some embodiments, the sintering system furtherincludes a curved surface located along the channel of the sinteringstation, where the tape material bends relative to a widthwise axis ofthe tape material around the curved surface as the tape material movesthrough the sintering station, thereby influencing shape of the tapematerial. In some embodiments, the exit and the entrance of thesintering station lie in a substantially horizontal plane, such that anangle defined between the exit and the entrance of the sintering stationrelative to a horizontal plane is less than 10 degrees, thereby at leastin part controlling flow of gases relative to the channel; for example,in some such embodiments, the sintering station further comprises anupward facing channel surface defining a lower surface of the channel,and a downward facing channel surface defining an upper surface of thechannel, where the downward facing channel surface is positioned closeto an upper surface of the tape material such that a gap between theupper surface of the tape material and the downward facing channelsurface is less than 0.5 inches, thereby at least in part controllingflow of gases in the channel. The tape material may be particularlywide, long, and thin, having a width greater than 5 millimeters, alength greater than 30 centimeters, and a thickness between 3micrometers and 1 millimeter, and the inorganic material of the tape maybe at least one of a polycrystalline ceramic material and syntheticmineral.

Other aspects of the present disclosure relate to a process formanufacturing ceramic tape, the process comprising a step of sinteringtape comprising polycrystalline ceramic to a porosity of thepolycrystalline ceramic of less than 20% by volume, by exposingparticles of the polycrystalline ceramic to a heat source to induce thesintering between the particles. The tape is particularly thin such thata thickness of the tape is less than 500 μm, thereby facilitating rapidsintering via heat penetration. Further, the tape is at least 5 mm wideand at least 300 cm long. In some embodiments, the process furtherincludes a step of positively lengthwise tensioning the tape during thesintering. In some such embodiments, the process further includes a stepof moving the tape toward and then away from the heat source during thesintering. In some embodiments, the amount of time of the sintering isparticularly short, that being less than two hours in aggregate, therebyhelping to maintain small grain size in the ceramic tape; for example,in some such embodiments, the time in aggregate of the sintering is lessthan one hour, and density of the polycrystalline ceramic after thesintering is greater than 95% dense by volume and/or the tape comprisesclosed pores after the sintering. In some embodiments, the tapecomprises a volatile constituent that vaporizes during the sintering,where the volatile constituent is inorganic, and where the tapecomprises at least 1% by volume more of the volatile constituent priorto the sintering than after the sintering.

Still other aspects of the present disclosure relate to a tapecomprising a body comprising grains of inorganic material sintered toone another. The body extending between first and second major surfaces,where the body has a thickness defined as distance between the first andsecond major surfaces, a width defined as a first dimension of the firstmajor surface orthogonal to the thickness, and a length defined as asecond dimension of the first major surface orthogonal to both thethickness and the width. The tape is long, having a length of about 300cm or greater. The tape is thin, having a thickness in a range fromabout 3 μm to about 1 mm. The tape is particularly wide, having a widthof about 5 mm or greater. According to an exemplary embodiment,geometric consistency of the tape is such that a difference in width ofthe tape, when measured at locations lengthwise separated by 1 m, isless than 100 μm; and a difference in thickness of the tape, whenmeasured at locations lengthwise separated by 1 m along a widthwisecenter of the tape, is less than 10 μm. In some embodiments, the tape isflat or flattenable such that a length of 10 cm of the tape pressedbetween parallel flat surfaces flattens to within 0.05 mm of contactwith the parallel flat surfaces without fracturing; and for example insome such embodiments, when flattened to within 0.05 mm of contact withthe parallel flat surfaces, the tape exhibits a maximum in plane stressof no more than 1% of the Young's modulus thereof. In some embodiments,the first and second major surfaces of the tape have a granular profile,where the grains are ceramic, and where at least some individual grainsof the ceramic adjoin one another with little to no intermediateamorphous material such that a thickness of amorphous material betweentwo adjoining grains is less than 5 nm. In some embodiments, the bodyhas less than 10% porosity by volume and/or the body has closed pores.In some embodiments, the grains comprise lithium, and the body has ionicconductivity of greater than 5×10⁻⁵ S/cm. In some embodiments, the bodyhas a particularly fine grain size, that being 5 μm or less. In someembodiments, the tape further includes an electrically-conductive metalcoupled to the first major surface of the body, where in some suchembodiments the body comprises a repeating pattern of vias, and theelectrically-conductive metal is arranged in a repeating pattern. Insome embodiments, the first and second major surfaces have a granularprofile, the tape further includes a coating overlaying the granularprofile of the first major surface, and an outward facing surface of thecoating is less rough than the granular profile of the first surface,where electrically-conductive metal coupled to the first major surfaceis so coupled by way of bonding to the outward facing surface of thecoating. In some embodiments, the inorganic material has viscosity of12.5 poise at a temperature greater than 900° C.

Additional aspects of the present disclosure relate to a roll of thetape of any one of the above-described embodiments, wherein the tape iswrapped around and overlapping itself, bent to a radius of less than 30cm.

Still other aspects of the present disclosure relate to a plurality ofsheets cut from tape of any one of the above-described embodiments.

Some aspects of the present disclosure relate to a tape, comprising abody comprising ceramic grains sintered to one another, the bodyextending between first and second major surfaces, where the body has athickness defined as distance between the first and second majorsurfaces, a width defined as a first dimension of the first majorsurface orthogonal to the thickness, and a length defined as a seconddimension of the first major surface orthogonal to both the thicknessand the width; where the tape is thin, having a thickness in a rangefrom about 3 μm to about 1 mm; and where first and second major surfacesof the tape have a granular profile, and at least some individual grainsof the ceramic adjoin one another with little to no intermediateamorphous material such that a thickness of amorphous material betweentwo adjoining grains is less than 5 nm.

Some aspects of the present disclosure relate to a tape, comprising abody comprising ceramic grains sintered to one another, the bodyextending between first and second major surfaces, where the body has athickness defined as distance between the first and second majorsurfaces, a width defined as a first dimension of the first majorsurface orthogonal to the thickness, and a length defined as a seconddimension of the first major surface orthogonal to both the thicknessand the width; where the tape is thin, having a thickness in a rangefrom about 3 μm to about 1 mm; where first and second major surfaces ofthe tape have a granular profile; and where the grains comprise lithiumand the body has ionic conductivity greater than 5×10⁻⁵ S/cm.

Additional features and advantages will be set forth in the detaileddescription that follows, and, in part, will be readily apparent tothose skilled in the art from the description or recognized bypracticing the embodiments as described in the written description andclaims hereof, as well as the appended drawings.

It is to be understood that both the foregoing general description andthe following detailed description are merely exemplary, and areintended to provide an overview or framework to understand the natureand character of the claims.

The accompanying drawings are included to provide a furtherunderstanding and are incorporated in and constitute a part of thisspecification. The drawings illustrate one or more embodiment(s), andtogether with the description serve to explain principles and theoperation of the various embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an example of distorted, sintered ceramic tape materialformed without technology disclosed herein, such as controlled greenribbon tensioning and other technology as discussed herein.

FIG. 2 shows an example of distorted, sintered ceramic tape materialproduced utilizing a temperature profile and tape speed which causednon-uniform sintering.

FIG. 3 is a roll-to-roll system for producing a sintered articleaccording to an exemplary embodiment.

FIG. 4 is an enlarged view of an embodiment of the separation systemshown in FIG. 3, according to an exemplary embodiment.

FIG. 5 is a side view of the continuous tape material, according to anexemplary embodiment.

FIG. 6 is a perspective view of a vacuum drum, according to an exemplaryembodiment.

FIG. 7 is an enlarged view of the vacuum drum shown in FIG. 6, accordingto an exemplary embodiment.

FIG. 8 is an enlarged view of the peeler shown in FIG. 4, according toan exemplary embodiment.

FIG. 9 is a conceptual side view of a station of a manufacturing line toprepare green tape for sintering, according to an exemplary embodiment.

FIG. 10 is a front perspective of the station of FIG. 9, according to anexemplary embodiment.

FIG. 11 is a block diagram of a method for processing a green tape to atleast in part prepare the green tape for sintering, according to anexemplary embodiment

FIG. 12 is a detailed view of the binder removal station and thesintering station of the system of FIG. 3, according to an exemplaryembodiment.

FIG. 13 is detailed view of tape material within the channel of thesintering furnace of FIG. 12, according to an exemplary embodiment.

FIG. 14 shows sintered tape material exiting a sintering furnace,according to an exemplary embodiment.

FIG. 15 is a view of the sintering station of FIG. 12 showing a heatingsystem, according to an exemplary embodiment.

FIG. 16 is a graph of a prophetic thermal profile and modeled sinteringshrinkage versus distance for different tape transport speeds, accordingto an exemplary embodiment.

FIG. 17 shows a prophetic sintering temperature profile projected alongthe channel of a sintering furnace, according to an exemplaryembodiment.

FIG. 18 shows an inline multi-furnace sintering station, according to anexemplary embodiment.

FIG. 19 shows prophetic temperature profiles for the two sinteringfurnaces of FIG. 18, according to an exemplary embodiment.

FIG. 20 shows a sintering system having two parallel production systems,according to an exemplary embodiment.

FIG. 21 is a graph of sintering shrinkage of a zirconia tape at varioustemperatures and times at temperatures including curves fit to the datafor each temperature.

FIG. 22 is a graph of a curve fit of a mathematical function of thesintering shrinkage of a zirconia tape at various temperatures and timesat various temperatures.

FIG. 23 is a modeled graph of peak stresses at the centerline of azirconia tape during sintering as a function of number of heating zones,passes, tape transport speed as a function of tape width.

FIG. 24 is a modeled graph of peak stresses at the edge of a zirconiatape during sintering as a function of the number of heating zones,passes, and tape transport speed as a function of tape width.

FIG. 25 is a modeled graph of shrinkage in a zirconia tape duringsintering using two passes through a single hot zone furnace for twotape transport speeds.

FIG. 26 is a modeled graph of stress in a zirconia tape during sinteringusing two passes through a single hot zone furnace for two tapetransport speeds.

FIG. 27 is a modeled graph of shrinkage in a zirconia tape duringsintering using two passes through a 10 hot zone furnace for two tapetransport speeds.

FIG. 28 is a modeled graph of stress (in MPa) in a zirconia tape duringsintering using two passes through a 10 hot zone furnace for two tapetransport speeds and various tape widths.

FIG. 29 is a perspective view of an illustration of a portion of asintered article, according to an exemplary embodiment.

FIG. 30A is a digital image of an unpolished surface of a sinteredarticle.

FIG. 30B is a conceptual side profile of the sintered article of FIG.30A.

FIG. 31A is a digital image of a polished surface of a sintered article.

FIG. 31B is a conceptual side profile of the sintered article of FIG.31A.

FIG. 32 is a side view along the width of a sintered article accordingto one or more embodiments.

FIG. 33 is a drawing to illustrate the thin bending equation.

FIG. 34A is a perspective side view of a rolled sintered article,according to an exemplary embodiment.

FIG. 34B is a cross-sectional view of the rolled sintered article ofFIG. 34A, according to an exemplary embodiment.

FIG. 35 is a height profile of the sintered article of Example 5, beforebeing flattened, showing the measured height above the flattening plane.

FIG. 36 is a height profile of the sintered article of Example 6, beforebeing flattened, showing the measured height above the flattening plane.

FIG. 37 is a height profile of the sintered article of ComparativeExample 7, before being flattened, showing the measured height above theflattening plane.

FIG. 38 is a height profile of the sintered article of ComparativeExample 8, before being flattened, showing the measured height above theflattening plane.

FIG. 39 is a plot of the maximum height above the flattening plane ofeach of the sintered articles of Examples 5-6 and Comparative Examples7-8.

FIG. 40 is a plot of the force required to flatten the sintered articlesof Examples 5-6 and Comparative Examples 7-8.

FIG. 41 is a plot of the pressure required to flatten the sinteredarticles of Examples 5-6 and Comparative Examples 7-8.

FIG. 42 is a plot of the maximum in plane stress after flattening in thesintered articles of Examples 5-6 and Comparative Examples 7-8.

FIG. 43A is a deformation plot showing measured stress in the bottomsurface of the sintered article of Example 5, after flattening.

FIG. 43B is a deformation plot showing measured stress in the topsurface of the sintered article of Example 5, after flattening.

FIG. 44A is a deformation plot showing measured stress in the bottomsurface of the sintered article of Example 6, after flattening.

FIG. 44B is a deformation plot showing measured stress in the topsurface of the sintered article of Example 6, after flattening.

FIG. 45A is a deformation plot showing measured stress in the bottomsurface of the sintered article of Comparative Example 7, afterflattening.

FIG. 45B is a deformation plot showing measured stress in the topsurface of the sintered article of Comparative Example 7, afterflattening.

FIG. 46A is a deformation plot showing measured stress in the bottomsurface of the sintered article of Comparative Example 8, afterflattening.

FIG. 46B is a deformation plot showing measured stress in the topsurface of the sintered article of Comparative Example 8, afterflattening.

FIG. 47 is a cross-sectional view of a segment of a package includingthe sintered article, according to an exemplary embodiment.

FIG. 48 is a length-wise cross-sectional view of a segment of a packageincluding the sintered article, according to an exemplary embodiment.

FIG. 49 is another cross-sectional view of a segment of a packageincluding the sintered article, according to an exemplary embodiment.

FIG. 50 is an example method of making a package including the sinteredarticle, according to an exemplary embodiment.

FIG. 51 is another example method of making a package including thesintered article, according to an exemplary embodiment.

FIG. 52 is an example cross-sectional view of a segment of a packageincluding the sintered article and a “flip-chip” configuration,according to an exemplary embodiment.

FIG. 53 is another example cross-sectional view of a segment of apackage including the sintered article and a “flip-chip” configuration,according to an exemplary embodiment.

FIG. 54 is yet another example cross-sectional view of a segment of apackage including the sintered article and a “flip-chip” configuration,according to an exemplary embodiment.

FIG. 55 is another cross-sectional view of a segment of a packageincluding the sintered article, according to an exemplary embodiment.

FIG. 56 shows a roll to roll system and related process for producing asintered article including a length of threading material, according toan exemplary embodiment.

FIG. 57 is a detailed view showing bonding between a length of threadingmaterial and tape material in the system of FIG. 56, according to anexemplary embodiment.

FIG. 58 shows a roll to roll system including a sintering stationconfigured to form a curve along a longitudinal direction of acontinuous length of tape material, according to an exemplaryembodiment.

FIG. 59 is a detailed view of a sintering station including an insertdefining a curved lower surface of a sintering channel, according to anexemplary embodiment.

FIG. 60 is a side view of a channel of a sintering station havingopposed curved upper and lower surfaces defining a sintering channel,according to an exemplary embodiment.

FIG. 61 is a side schematic view of a sintering station varying radiusesof curvature along the sintering channel, according to an exemplaryembodiment.

FIG. 62 shows a gas bearing having a curved upper surface that defines acurved surface of a sintering channel, according to an exemplaryembodiment.

FIG. 63 shows a roller arrangement for forming the longitudinal curve ina continuous length of tape during sintering, according to an exemplaryembodiment.

FIG. 64 shows an arrangement including multiple rollers for formingmultiple longitudinal curves in a continuous length of tape duringsintering, according to an exemplary embodiment.

FIG. 65 shows a free-loop arrangement for forming the longitudinal curvein a continuous length of tape during sintering, according to anexemplary embodiment.

FIG. 66 is a digital image of sintered tapes demonstrating flatteningproduced when the tape bent during sintering.

FIGS. 67A and 67B are digital images of a roll of sintered ceramic tapeaccording to an exemplary embodiment.

FIG. 68 is a digital image of a roll of a sintered ceramic tapeaccording to another embodiment.

FIG. 69 is a digital image of a roll of a sintered ceramic tapeaccording to yet another embodiment.

FIG. 70 is a graphical representation of time sintering for traditionalbatch firing versus the presently disclosed technology according to anexemplary embodiment.

FIGS. 71A and 71B are top views of surfaces of sintered articlesaccording to exemplary embodiments.

FIGS. 72A and 72B are side perspective views of surfaces of sinteredarticles according to exemplary embodiments.

FIGS. 73A, 73B, and 73C are micrographs of grain boundaries of sinteredarticles according to exemplary embodiments.

FIGS. 74 and 75 are micrographs of grain boundaries of sintered articlesaccording to other exemplary embodiments.

FIGS. 76 and 77 are top views of surfaces of sintered articles accordingto exemplary embodiments.

FIG. 78 is a digital image of a tape of a sintered article according toan exemplary embodiment.

FIGS. 79A and 79B are side views sintered articles according toexemplary embodiments.

FIG. 80 is a side view of a sintered article according to an exemplaryembodiment.

FIG. 81 is a side view of a sintered article according to anotherexemplary embodiment, where the sintered material appears amorphous.

FIG. 82 is a graphical representation of compositions.

FIGS. 83 and 84 are side perspective views of surfaces of sinteredarticles according to exemplary embodiments.

FIGS. 85A and 85B are side perspective views of surfaces of un-sinteredgreen material according to exemplary embodiments.

FIGS. 86A and 86B are side perspective views of surfaces of sinteredmaterial according to exemplary embodiments.

FIG. 87 is a graphical representation of viscosity versus temperaturefor various materials.

FIG. 88A is a graphical representation of a temperature profile througha sintering furnace according to an exemplary embodiment.

FIG. 88B is a schematic diagraph of the sintering furnace of FIG. 88A.

FIG. 89 is a schematic diagraph of a sintering furnace according toanother exemplary embodiment.

FIG. 90A is a graphical representation of a temperature profile througha sintering furnace according to another exemplary embodiment.

FIG. 90B is a schematic diagraph of the sintering furnace of FIG. 90A.

FIGS. 91A and 91B are side perspective views of surfaces of sinteredmaterial according to exemplary embodiments.

FIG. 92 is a side view of a sintered material according to an exemplaryembodiment.

FIG. 93 is a schematic diagraph of electronics in the form of a batteryaccording to an exemplary embodiment.

FIGS. 94 and 95 are graphical representations of sintering schedulesaccording to exemplary embodiments.

FIG. 96 is a graphical representation of sintering temperature versusionic conductivity for sintered articles according to exemplaryembodiments.

FIG. 97 is a graphical representation of sintering temperature versuspercentage of cubic garnet for sintered articles according to exemplaryembodiments.

FIGS. 98 and 99 are side perspective views of surfaces of sinteredmaterial according to exemplary embodiments.

FIGS. 100A and 100B are tops views of surfaces of one side of a sinteredmaterial and FIGS. 101A and 101B are tops views of surfaces of anotherside of the sintered material according to an exemplary embodiment.

FIG. 102 is a side view of a sintered material according to an exemplaryembodiment.

FIG. 103 is a digital image of a sintered material with a layerproviding a smooth surface according to an exemplary embodiment.

FIG. 104 is a schematic diagraph of electronics in the form of a stackof sintered articles according to an exemplary embodiment.

DETAILED DESCRIPTION

Referring generally to the figures, various embodiments of a system andprocess for manufacturing long, thin and/or wide sintered articles areshown and described, where by the term sinter Applicant refers to theprocess of coalescing (e.g., directly bonding to one another) particlesor grains (e.g., of a powdered or granular material) into a solid orporous body by heating the particles or grains without completelyliquefying the particles or grains such that crystal structure of theparticles or grains remain in the coalesced body, however aspects of thepresent inventive technology may be used to manufacture amorphousmaterial, such as those that are difficult or impossible to processusing conventional manufacturing techniques, as may be intuitive tothose of skill in the art of inorganic material processing. In addition,Applicant has discovered that new sintered articles having a variety ofproperties may be formed using the systems/processes discussed hereinthat were previously unachievable utilizing prior technology.Specifically, Applicant has developed material handling systems andprocesses that allow for a very precise level of control of a varietyconditions/forces that the material experiences during formation of thesintered article, and that this precise control/material handling allowsfor production of long, thin and/or wide sintered tape materialsbelieved to be unachievable with prior systems. Further, articlesmanufactured using technology disclosed herein may have other uniquequalities, such as: strength, such as may be due to low number defects;purity, such as may be due to controlled airflow and sintering duration,and properties related to purity, such as dielectric constant andimpermeability; consistency, such as along a length and/or widthwise,such as in terms of flatness, thickness, roughness, grain size, etc.;and other unique attributes.

In general, the system described herein utilizes an input roll of websupported green tape wound on a spool or reel. As explained in moredetail below, the web supported green tape includes a green tapematerial including grains of inorganic material (e.g., such as grains ofceramic material, grains of polycrystalline ceramic material, metalgrains or grains of synthetic material) bound with an organic bindermaterial, and the green tape material is supported on carrier web (e.g.,a sheet of polymer material). The input roll of web supported green tapeis unwound, and the carrier web/backing layer is carefully separatedfrom the green tape material. Applicant has found that by preciselycontrolling separation of the carrier web from the green tape withlittle or no distortion of the green tape, a sintered article havingvarious properties (e.g., thickness, flatness, density, shape etc.) thatare very consistent/controlled along its length can be produced. Withthat said, in other contemplated embodiments the green tape may not beweb supported and/or may not be on a roll, such as if the tape is formedin-line, such as along the manufacturing line prior to sintering.

Following removal of the carrier web, the self-supporting green tape(including the grains of inorganic material supported by organic bindermaterial) is moved through a binder removal station. In general, thebinder removal station applies heat to the self-supporting green tape ina manner that removes or chemically alters the organic binder such thatthe tape material exiting the binder removal station is an unbound tapematerial. By unbound, Applicants refer to the binder material havingbeen removed, however the unbound tape may still hold together, such asvia char of the burned binder or by interweaving or bonding between theinorganic particles, or by other means (e.g., electrostatic forces, airpressures). Following removal of the organic binder, the unbound tapematerial is moved into a sintering station that applies heat to theunbound tape material that sinters (e.g., fully sinters or partiallysinters) the inorganic particles forming a sintered article which exitsthe sintering station.

Applicant has found that, surprisingly, the grains of inorganic materialwill support themselves as an unbound tape material even after theorganic binder is removed and/or that the tape may be otherwisesupported, as described above. However, following removal of the organicbinder, the unbound tape material is very delicate prior to sintering ormay be very delicate prior to sintering. Thus, Applicant has furtheridentified a new binder removal and sintering station arrangement thatallows for handling of the delicate unsupported tape material in amanner that allows for production of very high quality sinteredarticles. (By unsupported in the preceding sentence, Applicant meansunsupported by organic binder after the binder has been removed orburned.) In particular, wide, long, high quality sintered articlessuitable for roll to roll handling are produced without introducingsubstantial distortion or without breaking the article during binderremoval or sintering.

In particular, Applicant has identified that air flow (e.g., turbulentair flow generated by thermal gradients) within the binder removalstation and/or sintering station may impinge upon the tape materialcausing distortion or breakage of the tape material. Further, Applicanthas discovered that a highly horizontal processing path within thebinder removal station and/or sintering station reduces or eliminatesturbulent airflow which in turn produces or may produce sinteredarticles without significant distortion. Further, Applicant hasdetermined that eliminating air flow based distortion is particularlyimportant when forming wide sintered articles (e.g., articles havingwidth greater than 5 mm) because Applicant believes that susceptibilityto air flow based distortion increases as the width of the tape materialincreases. Further, Applicant has determined that eliminating orreducing air flow based distortion is particularly important to allowfor roll to roll processing as Applicant has found that even minorlevels of distortion may cause the sintered article to break orotherwise not wind properly on the uptake reel (also called a tape-upreel).

Identification of horizontal positioning of the tape during binderremoval and/or sintering was a surprising discovery given the inorganicgreen material and prior sintering technologies. For example, some tapematerial sintering may use downwardly angled positioning (e.g., a 12 to20 degree downward incline) of the tape material as a means of utilizinggravity to pull the delicate tape material through the heating steps ofthe system, possibly intended for application of an evenly distributedforce across the tape material to pull the tape material through heatingsteps of the process.

However, Applicant has discovered that when the heating portions of asintering system are positioned at an incline, turbulent air flows mayform as the hot air rises through channels of the heating system thatholds the tape material. Thus, this flowing air impinges on the tapematerial, possibly forming distortions or potentially breaking the tape.Further Applicant discovered that incidence of air flow baseddistortions created in the sintered tape formed using a non-horizontalheating arrangement may increase as the width of the tape materialincreases. With that said, aspects of technology disclosed herein may beused with systems that include non-horizontal heating channels orsystems, such as a binder removal station. Further, aspects oftechnology disclosed herein, such as unique materials and form factors(e.g., thin ribbons of garnet or other materials or geometries), may bemanufactured using non-horizontal heating channels or systems.

Applicant attempted to sinter a wider tape (e.g. a tape having a widthgreater than 5 mm, and specifically a green tape of 25 micronsthickness, width of 32 mm, with zirconia—3 mole % Y₂O₃ inorganicparticles) using an incline arrangement. As shown in FIG. 1, whenpartially sintered at 1250° C., the partially sintered article formedhad significant and periodic distortions or bubbles along the length ofthe tape. The height of the distortion was on the order of greater than1 mm and were large enough to prevent spooling of the tape on a corehaving a diameter of 3-6 inches. Applicant believes that the bubbleswere formed as turbulent air flow pushed upward on the tape as the hotair flowed up the sloped support surface underneath the tape during theheated stages of tape processing (e.g., during sintering and binderremoval).

In addition to air flow control, Applicant has identified that controlof the thermal profiles within the binder removal station and/orsintering station is or may be important to forming a high qualitysintered article. In particular, Applicant has discovered that whenheating a wide tape material in a roll to roll process, such as the onediscussed herein, the thermal stresses that the tape material is exposedto, particularly during sintering, should be precisely controlled tolimit distortion or breakage that may otherwise occur as the tapematerial shrinks/densifies during sintering for at least some materialsand/or forms disclosed herein, such as at least some thin, wide tapes ofinorganic material. As an example shown in FIG. 2, a section of ceramictape (specifically alumina tape) including the portion of the tape atthe transition from unsintered to sintered material is shown as formedusing a process with steep temperature increases within the hightemperature sintering zone. As shown in FIG. 2, this steep temperatureincrease causes or may cause distortion or cross-web shape due to stressinternal to the tape material as the tape sinters following the fastrise in temperature in the sintering zone. With that said, in otherembodiments, such as for different materials (e.g., lithium garnet), asteep temperature increase may be beneficial, such as by reducingexposure to oxidation or impurities, and distortions may be controlledvia other factors, such as air flow control and narrower width of tapefor example.

Thus, as shown and described below, Applicant has determined that byutilizing a sintering furnace with independently controlled heatingzones and/or multiple independently controlled sintering furnaces, awide, long segment of tape material may be sintered without significantdistortion and/or breakage at a high process throughput rate. Similarly,the binder removal furnace and sintering furnaces are designed andpositioned relative to each other to limit the thermal shock (e.g.,exposure to a sharp temperature gradient) that the tape is exposed to asthe tape transitions between different heated zones within the systemdiscussed herein.

Following sintering, the wide, sintered tape is or may be wound onto anuptake reel forming a roll of sintered tape material. In contemplatedembodiments the roll is cylindrical or otherwise shaped, such as whenrolled around geometry that is not circular, such as oblong, triangularwith rounded vertices, etc. Because of the high quality (e.g., lowdistortion) of the tape formed by the system(s) discussed herein, in atleast some embodiments the tape may be wound into a roll in a mannerthat allows for the sintered tape roll be used conveniently andefficiently in subsequent manufacturing processes, e.g., as a substratein downstream, roll-to-roll manufacturing processes. Applicant has foundthat the high level of width, length, thickness, shape and/or flatnessconsistency and/or other attributes (purity, strength, impermeability,dielectric performance) of the tape or other articles produced by thesystem(s) discussed herein allows for spooling of the tape on the uptakereel. In contrast, a tape with high levels of distortion orirregularities would or may tend to break or otherwise form a distorted,inconsistent tape roll and may be unsuitable for uptake onto a reel toform a roll of sintered tape. With that said, some contemplatednon-horizontal sintering systems, especially those that employtechnology disclosed herein, may allow for undistorted tapes, such as ifair flow is controlled, the tape is thin enough and sufficientlytensioned, the rate of sintering and temperatures are controlled, forexample, as disclosed herein.

Lastly, some conventional sintered articles are formed in systems inwhich discreet unsintered pieces or pieces of green tape are placed upona surface, called a setter board, and placed inside a furnace that burnsoff the organic binder and sinters the inorganic grains. Applicant hasidentified that roll-to-roll formation of a sintered article willprovide a number of advantages not found by discreet, conventionallysintered articles. For example, wide, wound rolls of sintered articlescan be formed at high throughput speeds (e.g., speed of 6 inches perminute or greater). In addition, system(s)/process(es) discussed hereinforms wide, thin sintered (e.g., thin ceramic and/or sintered articles)which allows for use of the sintered article as a substrate to formsmall and low cost devices (e.g., semi-conductor devices, batteries,etc.). Similarly, providing a roll of sintered material allows thesintered material be used as an input substrate roll to high throughputdownstream manufacturing processes, further allowing for downstreamarticles to be formed at high speed and/or at low cost utilizing thesintered articles discussed herein.

System Overview

Referring to FIG. 3, a system 10 for producing a sintered tape articleis shown according to an exemplary embodiment. In general, green tapematerial is provided to system 10 at an input side, separation system12, and the green tape material moves through system 10 generally in theprocessing direction 14. Within separation system 12, a source 16 ofcontinuous tape material 18 (continuous' meaning long lengths, asdisclosed herein, such as 300 cm or longer, which can be provided in theform of a spool or belt) is provided, and is fed to the downstreamportions of system 10.

In general, continuous tape material 18 includes a layer of green tapematerial 20 that includes grains of inorganic, sinterable material boundtogether with an organic binder (e.g., (e.g., polyvinyl butyral, dibutylphthalate, polyalkyl carbonate, acrylic polymers, polyesters, silicones,etc.). The green tape material 20 of the continuous tape material 18 isor may be supported on a carrier web or backing layer 22. As will bediscussed in more detail below, in specific embodiments, system 10 isconfigured to form long, wide and/or thin sintered articles and in suchembodiments, the green tape material 20 coming into the system 10 isalso relatively long, wide and/or thin. For example, in specificembodiments, green tape material 20 has a width greater than 5 mm,greater than 10 mm, greater than 40 mm or greater than 125 mm. Inspecific embodiments, green tape material 20 has a length greater than10 meters (m), specifically greater than 30 m, and more specificallygreater than 60 m. In specific embodiments, green tape material 20 has athickness between 3 microns and 1 millimeter. In addition, incominggreen tape material 20 has a porosity that is greater than the porosityof the sintered article produced by system 10. In other contemplatedembodiments, the green tape material 20 may have a width less than 5 mm,such as at least 0.5 mm, at least 1 mm, at least 2.5 mm, or smaller than0.5 mm in some such embodiments. Similarly, the tape may have anotherthickness and/or length and/or porosity. In some embodiments, the tapematerial 20 may have a non-rectangular cross-section orthogonal to itslength, such as round, oblong, parallelogram, rhomboid, etc., where, asmay be intuitive, width of such embodiments refers to a maximumcross-sectional dimension orthogonal to length and thickness is aminimum cross-sectional dimension orthogonal to length.

Separation system 12 includes carrier web removal station 24. At carrierweb removal station 24, carrier web 22 is separated from green tapematerial 20, and the removed carrier web 22 is or may be wound onto anuptake reel 26. In general, carrier web removal station 24 includes atension isolator 28, which can include a vacuum drum, and a peeler 30that removes carrier web 22 in manner that does not distort or compressgreen tape material 20 and that isolates the tension within carrier web22 generated by uptake reel 26 from green tape 20. Following separationfrom carrier web 22, green tape 20, is or may be a self-supporting greentape including the grains of inorganic material supported by the organicbinder material, but does not include a carrier web or other supportstructure to hold the tape material together during downstreamprocessing through system 10.

Self-supporting green tape 20 moves or may move into an ultralow tensioncontrol system 32. In general, self-supporting green tape 20 is arelatively delicate structure that is being pulled through system 10 viathe operation of various spools, reels, rollers, etc. The pulling actionimparts a tension to self-supporting green tape 20. Applicant has foundthat a uniform, low level (e.g., gram levels; 0.1 grams to less than 1kg; at least 1 gram, at least 5 grams, and/or no more than 100 grams,depending upon the tape size and binder strength) of tension applied toself-supporting green tape 20 is or may be advantageous as it improvesvarious characteristics, such as cross-width shape and flatness of thefinal sintered article. However, due to the delicate nature of theself-supporting green tape 20 (which becomes even more delicatefollowing binder removal as described in more detail below), the lowlevel of tension is precisely controlled such that enough tension isprovided to tape 20 to limit distortion during binder removal/sinteringof tape 20 while also limiting maximum tension to ensure tape 20 doesnot break. With that said, in other contemplated embodiments, greatertension, such as for stronger tapes, or zero tension, other than tensiondue to weight of the tape itself, is applied.

In one or more embodiments, as shown in FIG. 3, tension control system32 includes an ultralow tension dancer 33 which utilizes light weight,low inertia carbon fiber rollers. Ultralow tension dancer 33 may includeair-bearings to facilitate low friction rotation of the carbon fiberrollers of tension dancer 33. In other embodiments, a free loop ofmaterial or a vacuum box may be utilized to provide consistent, gramlevels of tension to tape 20.

Following tension control system 32, self-supporting green tape 20 movesinto binder removal station 34. In general, binder removal station 34includes one more heating element that delivers heat to a channel formedwith the station 34. Heat within binder removal station 34 chemicallychanges and/or removes at least a portion of the organic binder materialof self-supporting green tape 20 such that an unbound tape 36 exitsbinder removal station 34. In general, unbound tape 36 includes thegrains of inorganic material with very little or no organic binderremaining. Applicant has found that unbound tape 36 will hold itselftogether even without the presence of the organic binder in manner thatallows the unbound tape 36 to be moved into sintering station 38, suchas utilizing the tension-control, air flow control, proximity of thebinder removal station 34 to the sintering station 38 and temperaturecontrol therebetween, orientation and alignment of the tape and stations34, 38 as shown in FIG. 3.

In general, binder removal station 34 is arranged and controlled in amanner that provides for low distortion of tape 20 as it traverses thebinder removal station 34. Further, binder removal station 34 mayinclude heating elements that allow for removal of volatile organiccompounds without applying too much heat too quickly, which otherwisemay ignite the organic binder compounds. Ignition may also be controlledby air flow.

In addition, binder removal station 34 is positioned in manner relativeto sintering station 38 such that the thermal shock or temperaturegradient that unbound tape 36 is exposed to during movement from binderremoval station 34 into sintering station 38 is low (e.g., spaced apart,but with pathways aligned linearly and respective openings alignedand/or close to one another, such as within 1 m, such as within 10 cm,such as within 2 cm, and/or closer). Applicant has found that due to thedelicate nature of unbound tape 36, limiting the thermal shockexperienced by the tape 36 between stations 34 and 38 further providesfor production of flat, consistent and/or unwarped sintered tape bylimiting/eliminating distortion that would otherwise occur due to thetemperature gradients experienced between stations 34 and 38.

In various embodiments, temperature within station 34 is preciselycontrolled to achieve the desired properties of tape 36 leaving station34. In various embodiments, the temperature within station 34 is between200 degrees Celsius (° C.) (or about 200° C.) and 500° C. (or about 500°C.), and station 34 is heated to provide a temperature profile along itslength such that very little or no binder material remains within thetape material exiting binder removal station 34. Further, in someembodiments, some sintering (e.g., shrinkage, increase in density,decrease in porosity, etc.) of the grains of inorganic material mayoccur during traversal of binder removal station 34.

Following binder removal in station 34, unbound tape 36 moves into thesintering station 38. In general, sintering station 38 includes one ormore heating element (see, e.g., further discussion of heating elementsand types thereof below) that heats sintering station 38 to temperaturesabove 500 degrees ° C. (e.g., between 500° C. (or about 500° C.) and3200° C. (or about 3200° C., such as 3200° C.±10% of 3200° C.)) whichcauses sintering of the grains of inorganic material of unbound tape 36.In general, the porosity of the inorganic material decreases duringsintering. This decrease in porosity may also result in a shrinkage(e.g., a reduction in width, thickness, length, etc.) of the tapematerial as the material is sintered, such as in sintering station 38.With some materials, during sintering, the elastic modulus can increase,the strength can increase, the shape of the porosity can change, withouta significant decreasing in porosity or significant shrinkage. In someembodiments, the sintering station 38 transforms the tape 38 into abisque material that is partially, but not fully sintered.

Applicant has found that as unbound tape 36 traverses sintering station38, the unbound tape 36 is susceptible to deformation or breakage whichmay be caused by a variety of forces that the unbound tape 36 encountersduring sintering. In particular, as noted above, Applicant hasdiscovered that forces caused by turbulent air flow through sinteringstation 38 is one source of significant deformation, and Applicant hasalso found that the stress internal to tape 36 during sintering isanother significant potential source of deformation. Based on thesediscoveries, Applicant has arranged or configured sintering station 38in variety of ways in order to limit these forces to produce a sinteredarticle having acceptably low levels of distortion.

In particular, as shown in FIG. 3, sintering station 38 is arranged in asubstantially horizontal arrangement such that unbound tape 36 traversesstation 38 in a substantially horizontal orientation. Applicant hasfound that by maintaining the substantially horizontal arrangement ofsintering station 38, turbulent airflow can be reduced or minimized,which in turn results in formation of a sintered tape material at theoutput of sintering station 38 that has low levels of deformation, lowlevels of cross-tape shape, and/or is flat. In various embodiments,Applicant believes that for various wide tape materials, low turbulenceand consequently low distortion can be achieved by maintaining an angleless than 10 degrees, specifically less than 3 degrees and even morespecifically less than 1 degree between the processing path of the tapematerial relative to the horizontal plane. In some embodiments, the tapemay move over an arced path that is generally horizontal, as discussedbelow. In still other embodiments, the path through the sinteringstation 38 may be more inclined than 10 degrees above horizontal, asdiscussed above.

As shown in the embodiment of FIG. 3, binder removal station 34 is alsopositioned in the substantially horizontal position such that turbulentair flow does not cause distortion, breakage, etc. during the heatingwith binder removal station 34. Similarly, binder removal station 34 isaligned in the vertical direction (i.e. so that the respective openingsare aligned and face one another) with sintering station 38 such thatunbound tape 36 remains in the horizontal position as tape 36 traversesfrom binder removal station 34 to sintering station 38.

In addition, Applicant has discovered that if unbound tape 36 is exposedto a temperature profile along the length of sintering station 38 thathas drastic rises/drops in temperature, high levels of stress are or maybe generated within tape 36 which in turn causes or may causedeformation or breakage of tape 36 during sintering. Further, Applicanthas discovered that the sintering stresses increase the risk ofdeformation as the width of tape 36 increases. Thus, based on thesediscoveries, Applicant has determined that by utilizing a sinteringstation 38 with multiple, independently controllable heating elements(and potential multiple sintering furnaces), a temperature profile alongthe length sintering station 38 can be generated that keeps the stresswith tape 36 below a threshold that Applicant has discovered that tendsto causes deformation or breakage based on a particular tapeconfiguration.

Following traversal of sintering station 38, a partially or fullysintered tape material 40 exits sintering station 38 and enters theoutput side, uptake system 42. Sintered tape material 40 is wound uponuptake reel 44. An interlayer support material 46 is paid off of a reel48. Support material 46 is wound unto uptake reel 44 such that a layerof support material 46 is or may be located between each layer or atleast some layers of sintered tape material 40 on uptake reel 44. Thisarrangement forms a roll or spool of supported sintered tape material50. In general, support material 46 is a compliant, relatively highfriction material that allows sintered tape material 40 to be held on touptake reel 44 at a relatively low wind tension. The compliance ofsupport material 46 can compensate for cross-web shape that may bepresent in tape 40 (sintered tape material 40). The support material 46also increases friction between adjacent layers of tape 40 (sinteredtape material 40) on reel 44 which limits tape 40 (sintered tapematerial 40) from sliding/telescoping of reel 44. Applicant believesthat without support material 46, sintered tape material 40 tends toslide off (e.g., telescope) of spool 50 at least in part because themodulus of sintered tape 40 (sintered tape material 40) is relativelyhigh, limiting the ability of tape 40 (sintered tape material 40) tostretch under wind tension, which in turn tends to or may result in poorroll integrity.

As discussed herein, system 10 is configured to form a sintered tapematerial 40 having low levels of distortion, low level risk of breakage,consistent properties along its length, etc. despite the width and/orlength of the sintered article. As Applicant has discovered, the risk ofdistortion and breakage of tape at various stages of system 10 mayincrease, particularly as the width of the tape increases. For example,in specific embodiments, sintered tape 40 (sintered tape material 40)has a width greater than 5 mm, greater than 10 mm, greater than 40 mm orgreater than 125 mm, and the various arrangements of system 10 discussedherein limit the deformation or breakage risk despite the width of thetape material. In other embodiments the sintered tape has a width lessthan 5 mm and/or at least 0.5 mm, such as at least 1 mm, such as atleast 2 mm.

In addition, the various material handling and heating mechanism(s) ofsystem 10 allow for sintered tape 40 (sintered tape material 40) to beformed at a high throughput rate. In specific embodiments, the roll toroll processing of system 10 allows for production of sintered tape atspeeds believed to be substantially faster than other sinteringprocesses, such as tunnel kiln processing in at least some instances,such as conventional tunnel kiln processing. In specific embodiments,system 10 is configured to produce sintered tape 40 at a rate of atleast 6 inches per minute, at least 8 inches per minute, at least 19inches per minute, at least 29 inches per minute, and at least 59 inchesper minute. In yet additional specific embodiments, system 10 isconfigured to produce sintered tape 40 at a rate of at least 3 inchesper minute for green tape 20 having a width greater than 50 mm, of atleast 5 inches per minute for green tape 20 having a width between 35 mmand 50 mm, of at least 9 inches per minute for green tape 20 having awidth between 15 mm and 35 mm, and of at least 10 inches per minute forgreen tape 20 having a width between 5 mm and 15 mm. In additionalspecific embodiments, system 10 is configured to produce sintered tape40 at a rate of at least 1 inches per minute (ipm) for green tape 20having a width greater than 50 mm, of at least 1.5 inches per minute forgreen tape 20 having a width between 35 mm and 50 mm, of at least 2inches per minute for green tape 20 having a width between 15 mm and 35mm, and of at least 3 inches per minute for green tape 20 having a widthbetween 5 mm and 15 mm.

Support Web Removal Station

Formation of the embodiments of the sintered articles described hereinincludes applying a uniform web tension to the green tape materialbefore and after sintering. The separation system according to one ormore embodiments of this disclosure is designed to apply such uniformweb tension, along with uniform velocity, to a green tape material as itis separated from a supporting carrier web. Accordingly support of webremoval, as disclosed herein, allows for consistency of the shape of thegreen tape material, reducing or eliminating instances of necking orcontracting of the green tape as well as reducing or eliminatinginstances of imprinting features of surfaces of the equipment on thegreen tape, which in turn may otherwise be present in the sintered tape.With that said, technology disclosed herein may be used without thesupport web removal station to produce new sintered tapes as disclosedherein, where the tapes may have characteristics attributed to the lackof support web removal station, such as changes in thickness, repeatingimprinted surface features, etc.

As noted above, system 10 includes a support web removal stationgenerally at the input side of system 10. One aspect of the support webremoval station includes a separation system 12. Referring to FIG. 4,the separation system 12 is configured to separate a green tape material20 from a carrier web 22 such that the green tape material 20 can beprocessed downstream. In one or more embodiments, a source 16 ofcontinuous tape material 18 to be separated is provided. As shown moreclearly in FIG. 5, the continuous tape material 18 includes the greentape material 20 supported on the carrier web 22. In FIG. 4, the source16 is provided in the form of a spool that unwinds the continuous tapematerial 18 to a carrier web removal station 24 (including a tensionisolator 28 and a peeler 30). In one or more embodiments, the source 16may include a belt or other form to feed a continuous tape material. Inother contemplated embodiments, a source of the green tape material maybe another station on the manufacturing line that continuously producesor may continuously produce green material, form and condition greentape for subsequent handling in the system(s) disclosed herein. Stillother contemplated embodiments may use green tape material separated byorganic material that is burned or otherwise removed, such as by thebinder removal station disclosed herein.

According to an exemplary embodiment, the green tape material 20includes grains of inorganic material (as described herein) that aresinterable and are bound together with an organic binder. The carrierweb 22 may include a polymer, paper or a combination of a polymer and apaper material. In some embodiments, the green tape material includes anamount of polymer that is less than the polymer content of the carrierweb 22, where polymer content is in terms of volume percent of therespective material. According to an exemplary embodiment, the greentape material 20 and the carrier web 22 each have a respective thickness(t) defined as a distance between the first major surface and the secondmajor surface, a respective width (W) defined as a first dimension ofone of the first or second surfaces orthogonal to the thickness, and arespective length (L) defined as a second dimension of one of the firstor second surfaces orthogonal to both the thickness and the width, suchas for green tape having a continuous cross-sectional geometry that isrectangular or oblong (e.g., where edges may be removed after sinteringto form straight sides). In other contemplated embodiments, a tape ofinorganic, sinterable material may be held together by an inorganicbinder, such as an inorganic binder that becomes part of the sinteredtape after processing in the system 10. In still other contemplatedembodiments, the tape of inorganic material may be held together bybonding of the inorganic material to itself, such as with a partiallysintered bisque tape as opposed to green tape, as disclosed herein, forexample.

As will be described herein, according to an exemplary embodiment, thecarrier web 22 provides or may provide the primary contact surface forconveying the continuous tape material through the separation system 12and, in particular conveying the continuous tape material through thecarrier web removal station 24. In other words, in at least some suchembodiments the carrier web 22 is primarily contacted, leaving the greentape material 20 substantially uncontacted and thus, is substantiallyfree of defects or flaws that are or may be generated by contact, suchas repeating surface features due to imprinting of the surface of awheel or roller on the green material of the tape that may be detectablein a finished sintered product. Other embodiments may include suchdefects or flaws, such as when aspects of technology disclosed hereinare used without the carrier web removal station 24, for example.

When the source 16 is a spool, the continuous tape material has a firsttension, which is relatively low (as will be further described herein)and has a propensity to unwind at relatively high speeds even when thecontinuous material is held in a constant and low tension. Theseparation system 12 functions or may function as a brake to reduce orotherwise control or limit the speed of unwind of the continuous tapematerial from the source 16.

According to at least some such exemplary embodiments, the carrier webremoval station 24 includes a tension isolator 28 positioned inproximity to and downstream from the source 16 and a peeler 30positioned downstream from the tension isolator 28. The tension isolator28 and peeler 30 separate the carrier web 22 from green tape material 20without damaging the green tape material. In particular the tensionisolator 28 is designed and used to grip the carrier web and pace thevelocity of the continuous tape material through the separation system.In one or more embodiments, after the carrier web 22 is separated fromthe green tape material, the speed at which the carrier web 22 iscollected after separation from the green tape material 20 is controlledto maintain constant tension in the carrier web 22, and thus in thecontinuous green tape material 20. In one or more embodiments, thetension isolator 28 isolates the separation of the carrier web 22 fromthe green tape material 20 from the quality of the incoming green tapematerial 20 from the source 16. Without the tension isolator 28, any orsome inconsistencies in the wind quality of the continuous tape material(i.e. too loose a wind, which can result in cinching during unwinding orfeeding to the peeler 30) can cause tension and velocity variations atthe peeler 30.

According to an exemplary embodiment, the continuous tape material 18 isfed at a first tension to the tension isolator 28, and the tensionisolator of one or more embodiments has a structure or is configured toapply a second tension to carrier web 22, which is greater than thefirst tension of the continuous tape material 18, when conveying thecontinuous tape material 18 to the peeler 30. In some embodiments, thesecond tension (i.e. tensile force) is at least 20% greater than thefirst tension and/or at least 25 millinewtons (mN) greater, such as atleast 100 mN greater, such as at least 200 mN greater. According to somesuch embodiments, the second tension is applied to the carrier web 22,but not or at least substantially not applied to the green tapematerial. In one or more embodiments, the green tape material 20maintains the first tension as the continuous tape material is movedalong the tension isolator 28. In one or more embodiments, as thecontinuous tape material is moved along the tension isolator 28, thegreen tape material comprises or has no tension or no tension beyondtension to support its own weight, or substantially no tension beyondtension to support its own weight, such as less than 1 newton (N) beyondtension to support its own weight. Accordingly, the tension isolator 28creates a first tension zone 17 between the tension isolator 28 and thesource 16 and a second tension zone 19 between the tension isolator 28and the peeler 30. The tension applied to the carrier web 22 in thefirst tension zone 17 is less than the tension applied to the carrierweb 22 in the second tension zone 19. In one or more embodiments, thetension (i.e. tensile stress) applied to the carrier web 22 in thesecond tension zone 19 is about 2.5 pounds per (linear) inch (PLI) orless. For example, in one or more embodiments, the tension applied tothe carrier web 22 is about 2.4 PLI or less, about 2.3 PLI or less,about 2.2 PLI or less, about 2.1 PLI or less, about 2 PLI or less, about1.8 PLI or less, about 1.6 PLI or less, about 1.5 PLI or less, about 1.4PLI or less, about 1.2 PLI or less, or about 1 PLI or less. In one ormore embodiments, the first tension is equal to or less than about 50%(e.g., about 45% or less, about 40% or less, about 35% or less, about30% or less, or about 25% or less) of the second tension. In someembodiments, tension (i.e. tensile force) applied to the carrier web 22in the second tension zone 19 is at least 20% greater than tensionapplied to the carrier web 22 in the first tension zone 17 and/or atleast 25 millinewtons (mN) greater, such as at least 100 mN greater,such as at least 200 mN greater. In one or more embodiments, (nominal)additional tension is applied to the green tape material, other than thetension that is applied on the green tape material through theapplication of tension on the carrier web 28. In such embodiments, thecarrier web may stretch due to such application of tension on thecarrier web, which in turn creates some tension on the green tapematerial, such as where the overwhelming bulk of tension is borne by thecarrier web.

In one or more embodiments, the tension isolator 28 applies a tension tothe carrier web 22 that is greater than the tension applied to the greentape material 20. In some embodiments, the tension isolator applies atension to the carrier web that is equal to or greater than about 2times the tension applied to the green tape material, as the continuoustape material is moved from the source 16 to the peeler 30. In someembodiments, the tension isolator 28 applies a tension to the carrierweb 22 that is at least 20% greater than the tension applied to thegreen tape material 20 and/or at least 25 millinewtons (mN) greater,such as at least 100 mN greater, such as at least 200 mN greater. As maybe intuitive, tension as used herein generally refers to the lengthwiseor axial pulling apart of material and when given units of force herein,tension refers to tensile force, and when given units of stress, tensionrefers to tensile stress, and/or tension herein may be given other unitsand refer to another related parameter, such as pounds per linear inchor the metric equivalent.

In the embodiment shown in FIG. 4, the tension isolator 28 may include avacuum drum 25. As illustrated in FIG. 6, in one or more embodiments,the vacuum drum 25 is rotated to move the continuous tape material by adrive motor input 27, which is connected to the vacuum drum by a bearinghousing 29. As shown in FIG. 7, the vacuum drum may include an outersurface including a plurality of vacuum holes 7 disposed in a uniformdistribution. The vacuum holes 7 may be formed along a plurality ofaxial grooves 8 and/or radial grooves, which intersect one another at avacuum hole 7. A vacuum is supplied to the vacuum drum 25 via a vacuumsource (e.g., a vacuum blower), which through the vacuum holes 7, gripsthe carrier web 22, thereby facilitating tensioning the carrier web, asdescribed herein. In one or more embodiments, the distribution of thevacuum holes 7 and the configuration of the vacuum drum (including thediameter and vacuum force utilized) apply or help to apply a uniformtension to the carrier web along the width of the carrier web. Throughthis action and configuration, the vacuum drum paces the velocity of thecarrier web (and thus the continuous tape material) as it travelsthrough the separation system 12. In one or more embodiments, thetension isolator pulls the continuous tape material from the sourcealong the first tension zone 17. Any or some inconsistencies in thedelivery of the green tape material from the source 16 to the peeler 30,such as a loose wind (which can result in cinching during conveyancefrom the source to the peeler) do not or may not affect the separationprocess. Vacuum drum 25 provides a bonding or attracting force betweenthe tape material (e.g. carrier web) and the vacuum drum 25 in additionto normal force and friction that are proportional to tension, thusincreasing the bonding or attracting force without necessarilyincreasing tension in the tape material. At least because of thisadvantage, Applicants believe that use of a vacuum drum to control thebonding or attracting force between the tape material and a roller (i.e.the vacuum drum) during the step of separating the green tape from thecarrier web is a unique and effective process for protecting andcontrolling the shape of the green tape, which may be particularlydelicate. With that said, aspects of the present technology may be usedto create new sintered products, such as tapes that do have the indiciaof separation without use of a vacuum drum as disclosed herein, such asrepeating defects from rollers, changes in tape thickness, shorterlengths of tape, etc.

In one or more embodiments, the tension isolator 28 increases tension inthe continuous tape material (and more particularly in the carrier webor mostly the carrier web) along the second tension zone 19 as thecontinuous tape material is conveyed to the peeler 30. In the embodimentshown in FIG. 4, the separation system 12 includes a load controller 21to maintain the tension on the carrier web. In one or more embodiments,the load controller 21 is also used to adjust the velocity of the uptakereel 26 relative to the tension isolator 28.

In one or more embodiments, the peeler 30 is disposed downstream fromthe tension isolator 28 and directs the carrier web 22 in a rewinddirection A and directs the green tape material 20 in a downstreamprocessing direction B that differs from the rewind direction A, asshown in FIG. 8. In one or more embodiments, the rewind direction A andthe downstream processing direction form an angle C that is greater thanabout 90 degrees (e.g., 95 degrees or greater, 100 degrees or greater,110 degrees or greater or about 120 degrees or greater).

In one or more embodiments, the peeler 30 includes a sharp knife or edgeto create a line of separation in the green tape material, such as at orproximate to the vertex of the angle C, shown as tip 31. In one or moreembodiments, the sharp knife or edge creates a line of separation in thegreen tape material, but not the carrier web, just prior to a tip 31 orproximate to the tip 31, as shown in FIG. 8. In one or more embodiments,the tip has a radius of about 0.05 inches or less (e.g., about 0.04inches or less, about 0.035 inches or less, about 0.03125 inches orless, about 0.03 inches or less, or about 0.025 inches or less).

As continuous tape material passes over the tip 31, the tip 31 separatesthe carrier web 22 from the green tape material 20. In one or moreembodiments, the tip 31 separates the carrier web 22 from the green tapematerial 20 before directing the carrier web in the rewind direction Aand directing the green tape material in the downstream processingdirection B. In one or more embodiments, the tip 31 separates thecarrier web 22 from the green tape material 20 simultaneously withdirecting the carrier web 22 in the rewind direction A and directing thegreen tape material 20 in the downstream processing direction B.

As shown in FIG. 4, the separation system 12 includes an uptake reel 26for collecting the separated carrier web 22. In the embodiment shown, anoptional idle roller 23 may be used to further control and maintaintension in the carrier web 22. In one or more embodiments, sensors 15may also be used to control and maintain tension in the carrier web asthe source 16 diameter decreases and the uptake reel 26 diameterincreases, as more continuous tape material is conveyed through theseparation system.

Another aspect of the support web removal station pertains to a methodfor separating two materials (e.g., the green tape material and thecarrier web). In one or more embodiments, the method includes feedingthe continuous tape material 18 to the tension isolator 28, applyingtension to the carrier web 22 that is greater than a tension applied tothe green tape material 20 with the tension isolator, and directing thecarrier web to move in the rewind direction and directing the green tapematerial in a downstream processing direction that differs from therewind direction, as described herein. In one or more embodiments, themethod includes separating the carrier web from the green tape materialbefore directing the carrier web in a rewind direction and directing thegreen tape material in the downstream processing direction. In one ormore embodiments, the method includes separating the carrier web fromthe green tape material simultaneously with directing the carrier web inthe rewind direction and directing the green tape material in thedownstream processing direction. As taught above, embodiments of thismethod have the carrier web contacting the vacuum drum. In otherembodiments, tape materials may have carrier webs on both sides of thetape, and elements of the separation station may be repeated and used toremove both carrier webs.

In one or more embodiments, the method includes applying no tension orsubstantially no or very little tension (as disclosed above) to thegreen tape material. In one or more exemplary embodiments, the methodincludes applying no tension or substantially no or very little tensionto the green tape material as the continuous tape material moves fromthe source 16 to the tension isolator 28 along the first tension zone17. In one or more exemplary embodiments, the method includes applyingno tension or substantially no or very little tension to the green tapematerial as the continuous tape material moves from the tension isolator28 to the peeler 30 along the second tension zone 19. In one or moreembodiments, the method includes applying no tension or substantially noor very little tension to the green tape material 20 as the continuoustape 18 moves from the source 16 to the tension isolator 28 (along thefirst tension zone) and to the peeler 30 (along the second tensionzone). In one or more embodiments, the method includes applying tensionto the carrier web 22 that is at least two times greater than thetension applied to the green tape material 20 (at any point along theseparation system 12). Selecting a carrier web with low elasticity mayfacilitate having the carrier web bear a bulk of tension applied to thetape material.

In one or more embodiments, the method includes applying no additionaltension to the green tape material, other than the tension that isapplied on the green tape material through the application of tension onthe carrier web 28. In such embodiments, the carrier web may stretch dueto such application of tension on the carrier web, which in turn createssome tension on the green tape material. In one or more exemplaryembodiments, the method includes applying no additional tension to thegreen tape material as the continuous tape material moves from thesource 16 to the tension isolator 28 along the first tension zone 17. Inone or more exemplary embodiments, the method includes applying noadditional tension to the green tape material as the continuous tapematerial moves from the tension isolator 28 to the peeler 30 along thesecond tension zone 19. In one or more embodiments, the method includesapplying no additional tension to the green tape material 20 as thecontinuous tape 18 moves from the source 16 to the tension isolator 28(along the first tension zone) and to the peeler 30 (along the secondtension zone).

In one or more embodiments, the method for separating two materials(i.e., the green tape material and the carrier web) includes feeding thecontinuous tape material to the tension isolator and applying a firsttension to the carrier web, applying a second tension to the carrier webthat is greater than the first tension, and directing the carrier web tomove in a rewind direction and directing the green tape material in adownstream processing direction that differs from the rewind direction.In one or more embodiments, applying a first tension comprises applyingno tension or little tension as disclosed herein. In one or moreembodiments, applying a first tensions comprises applying no or littletension to the carrier web as the continuous tape material moves fromthe source 16 to the tension isolator 28 along the first tension zone.In one or more embodiments, the second tension is about 2.5 PLI or less.For example, in one or more embodiments, the tension applied to thecarrier web 22 is about 2.4 PLI or less, about 2.3 PLI or less, about2.2 PLI or less, about 2.1 PLI or less, about 2 PLI or less, about 1.8PLI or less, about 1.6 PLI or less, about 1.5 PLI or less, about 1.4 PLIor less, about 1.2 PLI or less, or about 1 PLI or less. In one or moreembodiments, the first tension is equal to or less than about 50% (e.g.,about 45% or less, about 40% or less, about 35% or less, about 30% orless, or about 25% or less) of the second tension.

In one or more embodiments, the method includes at least partiallysintering the green tape material (as will be discussed in more detailherein related to the sintering station), after it is separated from thecarrier web 22. In one or more embodiments, the method includes spoolingthe carrier web 22 onto an uptake reel 26, after the carrier web 22 isseparated from the green tape material 20. In one or more embodiments,the method includes continuously maintaining the tension on the carrierweb 22 along the second tension zone and until the carrier web isspooled onto the uptake reel.

Binder Removal Station

As noted above regarding FIG. 3, system 10 includes a heating stationconfigured to remove binder material from green tape 20 which, in atleast some embodiments, is actively and independently heated separatelyfrom the sintering stations. In other embodiments, such as with firingof bisque tapes as disclosed herein, there may be no heating station.Applicant believes that actively heating a station dedicated to binderremoval with its own controllable heat source, independent of heaterswithin the sintering furnace, allows for greater control of the binderremoval process, reducing likelihood of combustion of volatiles in thebinder of the green tape, which is particularly beneficial for widegreen tapes (e.g., at least 5 mm, at least 10 mm, at least 30 mm, atleast 50 mm). Other embodiments include passively-heated binder removalstations disclosed herein, where the stations use heat emitted from anadjoining sintering furnace.

According to an exemplary embodiment, as shown in FIG. 3, a binderremoval station 34 receives green tape 20 from separation station 12,and green tape 20 then advances through the binder removal station 34.Referring now to FIG. 9, a detailed view of binder removal station 34 ofsystem 10 is shown and described in more detail.

As discussed above, the green tape 20 includes grains of an inorganicmaterial bound by a binder as disclosed herein, such as an organicbinder. The binder removal station 34 receives the green tape 20 andprepares the green tape 20 for sintering by chemically changing thebinder and/or removing the binder from the green tape 20, leaving thegrains of the inorganic material, to form self-supporting, unbound tape36, which may be moved in the processing direction 14 into sinteringstation 38, as discussed in more detail below. According to an exemplaryembodiment, at an instant (i.e. a single moment in time) the green tape20 simultaneously extends toward, into, through, within, adjacent to,and/or away from the station 34. Accordingly, as will be understood, thetape material being processed in system 10 simultaneously includes thegreen tape 20 which is continuously connected to unbound tape 36, as thetape material traverses binder removal station 34.

According to an exemplary embodiment, the binder of the green tape 20may be a polymer binder and the binder is chemically changed and/orremoved from the green tape 20 by heating the binder to burn or char thebinder. According to an exemplary embodiment, the binder removal station34 chars or burns at least most of the organic binder in terms of weightfrom the first portion of the green tape 20 without sintering the grainsof the inorganic material, which can be measured by weighing the greentape before binder removal at the station 34 as well as the inorganicmaterial prior to forming the green tape, then weighing the unbound tape36 following operation of the binder removal station 34 and comparingdifferences. If remnants of the binder remain, such as carbon, Applicantbelieves that subsequent sintering, at higher temperatures, maygenerally remove those remnants. In other contemplated embodiments, thebinder may be chemically removed, such as formed from a materialselected to chemically react with another material (e.g., catalyst, gas)delivered to the green tape at a binder removal station prior tosintering. In still other contemplated embodiments, the binder may beevaporated or otherwise vaporized and outgassed from the green tape 20at a station prior to sintering.

Still referring to FIG. 9, according to an exemplary embodiment, thebinder removal station 34 comprises an active heater 5120 to char orburn at least most of the organic binder from the green tape 20 as thegreen tape 20 interfaces with the binder removal station 34 to form theunbound tape 36 (e.g., by reducing weight of the portion of the greentape 20 that is not inorganic material to be sintered by greater than50%, such as greater than 70%, such as greater than 90%; by reducingweight of the overall green tape 20 by greater than 30%, such as greaterthan 50%). The active heater 5120 provides heat energy to the green tape20 to burn out the binder. In some embodiments, the heater 5120 is orincludes an electrical heating element, such as an inductive orresistive heating element. In other embodiments, the heater 5120 is orincludes a combustion heating element, such as a gas heating element. Instill other embodiments, the heater 5120 is or includes a microwaveand/or a laser or other heating element. Such heating elements may alsobe used in the sintering station 38, but heat to different temperaturesas disclosed herein.

According to an exemplary embodiment, the active heater 5120 of thebinder removal station 34 includes heating zones, such as zones 5120A,5120B, 5120C, 5120D such that the rate of heat energy received by thegreen tape 20 increases as the green tape 20 advances through the binderremoval station 34. In some embodiments, the rate of heat energyreceived by the green tape 20 increases in a nonlinear manner, such asslowly increasing at first, as the binder degrades and emits combustiblegaseous byproducts, and then faster as the potential for the green tape20 catching fire is reduced. This heat zone approach and morespecifically the non-linear approach may be particularly useful forsintering of tapes, as disclosed herein, which may travel amanufacturing line, such as system 10, at a constant rate. According toan exemplary embodiment, temperatures experienced by the green tape 20in the binder removal station 34 may be at least 200° C., such as atleast 250° C., and/or below a sintering temperature for the inorganicgrains carried by the green tape 20, such as less than 1200° C., such asless than 900° C. In contemplated embodiments, for at least somematerials disclosed herein, the binder removal station 34 may sinter, atleast to some degree, inorganic material of the tape, such as possiblybonding individual grains to one another, which may increase tensilestrength of the tape.

According to an exemplary embodiment, the binder removal station 34blows and/or draws gas over and/or under (e.g., over and under) thegreen tape 20 as the green tape 20 advances through the binder removalstation 34. In some embodiments, the heater 5120 may provide a flow ofhot air to communicate some or all of the heat energy to the green tape20, as may be delivered through an array of nozzles through a wall froma plenum, or through a porous wall material. In other embodiments, flowof the gas is facilitated by fans or pumps adjoining the binder removalstation 34, such as fan 5122 shown in FIG. 9. Tanks of pressurized gasmay also be used as sources to supply gas to be blown over the tape. Insome embodiments, the gas is air. In other embodiments, the gas is aninert gas, such as argon.

In some embodiments, gas is blown and/or drawn over both the topside andunderside of the green tape 20, while in other embodiments, the gas isdirected only over the topside or the underside. In some suchembodiments, the green tape 20 is directly supported by a gas bearingand/or an underlying surface and moves relative to that surface. Forexample, the green tape 20 may slide along and contact an underlyingsurface, such as a surface made of stainless steel. In some embodimentsthe gas is heated to a temperature above room temperature before blowingor drawing it over the tape, such as to at least 100° C., whichApplicants have found may help prevent thermal shock of the green tape20, which may influence properties of resulting sintered material, suchas providing increased strength or flatness due to fewer sites ofsurface irregularities and stress concentrations.

Actively blowing or drawing gas over the green tape 20, especially airor gas containing oxygen, may be counterintuitive to those of skill inthe art because one might expect the oxygen to fuel and promote the tapecatching fire, which could distort the shape of the green tape 20 and/orotherwise harm quality of the green tape 20 as tape 20 traverses station34. However, Applicant has found that as the green tape 20 is conveyedthrough the binder removal station 34, blowing and/or drawing gas,including air in some embodiments, over the green tape 20 actually helpsthe tape not to catch fire. For example, Applicant has found that whilethe binder is removed and/or charred by the binder removal station 34without catching fire, that the tape catches fire when moving at thesame rate through the station 34 if air is not blown over the green tape20. Applicant contemplates that risk of catching the green tape 20 onfire may also be reduced and/or eliminated by moving the green tape 20slower through the binder removal station 34, further spacing apart theheat zones 5120A, 5120B, 5120C, 5120D, using flame retardants in thebinder and increasing ventilation of the binder removal station 34,and/or combinations of such technologies.

While gas may be actively blown and/or drawn over the green tape 20and/or the unbound tape 36, Applicant has found that the unbound tape 36may be particularly susceptible to damage from vibration and/orout-of-plane bending depending upon how the gas flows. Accordingly, insome embodiments, the gas flowing through the binder removal station 34is and/or includes laminar flow. The flow of the air may be diffusedand/or may not be directed to the unbound tape 36. In some embodiments,a gas source or motivator (e.g., fan, pump, pressurized supply) deliversat least 1 liter of gas per minute through the binder removal station34, such as through the passage 5128 (see FIG. 10).

According to some embodiments, the green tape 20 advances horizontally,not vertically through the binder removal station 34. Orienting the tapehorizontally may help control airflow through the binder removal station34, such as by reducing a “chimney effect,” where hot gasses rise andpull too much air through the binder removal station 34, vibrating theunbound tape 36. Air pumps, fans, and surrounding environmental airconditions (e.g., high temperatures) offset and/or control the chimneyeffect without horizontally orienting the green tape 20 through thebinder removal station 34 in other contemplated embodiments.

According to an exemplary embodiment, the unbound tape 36 is underpositive lengthwise tension as the green tape 20 advances throughstation 34. Tension in the green tape 20 may help hold the green tape 20in a flat orientation, such as if the green tape 20 subsequently passesinto another station of the manufacturing system for further processing,such as a sintering station 38. Without the binder (e.g., followingbinder removal in station 34), the unbound tape 36 may be weaker thanthe green tape material 20, such as having lesser ultimate tensilestrength, such as half or less, such as a quarter or less. According toan exemplary embodiment, lengthwise tension (i.e. tensile stress) in theunbound tape 36 is less than 500 grams-force per mm² of cross section.Applicant believes the green tape 20 is substantially more bendable thanthe unbound tape 36 such that a minimum bend radius without fracture ofthe green tape 20 is less than half that of the unbound tape 36 (e.g.,less than a quarter, less than an eighth), when measured via ASTMstandards, see E290, where bend radius is the minimum inside radius therespective portions of the green tape 20 can bend about a cylinderwithout fracture.

In at least some embodiments, following processing through the binderremoval station 34, the unbound tape material 36 moves into sinteringstation 38 (discussed in more detail below), which at least partiallysinters the inorganic material of the unbound tape 36 to form sinteredtape 40. Accordingly, for continuous processing, at an instant the greentape 20 is continuously connected to sintered tape 40 by way of theunbound tape 36.

In some such embodiments, binder removal station 34 is close to thesintering station 38 such that distance therebetween is less than 10 m(e.g., less than 10 mm, less than 2.5 cm, less than 5 cm, less than 10cm, less than 25 cm, less than 100 cm, less than 5 m, etc. between theoutlet opening of the binder removal station 34 and the entrance opening106 (see FIG. 12) of the sintering station 38) thereby mitigatingthermal shock that unbound tape 36 may experience in the gap betweenstation 34 and station 38, which may influence properties of resultingsintered material, such as providing increased strength or flatness dueto fewer sites of surface irregularities and stress concentrations. Incontemplated embodiments, binder removal station 34 is in direct contactwith and adjoins the sintering station 38 and/or is under a commonhousing therewith, however in at least some such embodiments anintermediate vent draws away fumes or other byproducts of the binderremoval.

Referring now to FIG. 10, the binder removal station 34 includes walls5126 defining a passage 5128 having inlet and outlet openings 5130, 5132on opposing ends of the passage 5128. The passage has a length L betweenthe inlet and outlet openings 5130, 5132, which in some embodiments isat least 5 cm, such as at least 10 cm, and/or no more than 10 m.According to an exemplary embodiment, the outlet opening 5132 and/or theinlet opening 5130 is narrow and elongate, such as having a height H anda width W orthogonal to the height H where the height H is less thanhalf the width W, such as less than a fifth the width W, such as lessthan a tenth the width W. In some such embodiments, the height H is lessthan 5 cm, such as less than 2 cm, such as less than 1 cm, and/or atleast greater than a thickness of green tape 20 to be processed thereby,such as at least greater than thicknesses of green tape disclosedherein, such as at least greater than 20 μm. Applicant has found thathaving a narrow opening(s) improves performance of the binder removalstation 34 by limiting circulation of gas (e.g., ambient airflow) at theinlet and outlet openings 5130, 5132. In some embodiments, the passage5128 is straight, while in other embodiment the passage is gentlyarcing, such as having a radius of curvature of greater than 1 m, wherethe arcing and corresponding curvature of the tape may help shape orflatten the tape.

Referring to FIG. 11, a method of processing tape 5210 includes a stepof advancing tape through a manufacturing system 5212 (e.g., binderremoval station 34 or other manufacturing systems disclosed herein),such as where the tape includes a first portion having grains of aninorganic material bound by a binder (e.g., green tape 20). The methodfurther includes a step of preparing the tape for sintering 5214 byforming a second portion of the tape (e.g., unbound tape 36) at astation of the manufacturing system by chemically changing the binderand/or removing the binder from the first portion of the tape, leavingthe grains of the inorganic material, thereby forming a second portionof the tape.

In some such embodiments, the step of preparing the tape for sintering5214 further comprises charring or burning at least most of the binderfrom the first portion of the tape (e.g., as discussed above) with orwithout contemporaneously sintering the grains of the inorganicmaterial. In some embodiments, the station of the manufacturing systemis a first station and the method of processing 5210 further comprisessteps of receiving the second portion of the tape at a second station5218, and at least partially and/or further sintering the inorganicmaterial of the second portion of the tape 5220 at the second station toform a third portion of the tape.

In some embodiments, the method of processing 5210 further comprisespositively tensioning the second portion of the tape as the tapeadvances 5212. In some such embodiments, positively tensioning is suchthat lengthwise tension (i.e. tensile stress) in the second portion ofthe tape is less than 500 grams-force per mm² of cross section. In someembodiments, the method of processing 5210 further comprises blowingand/or drawing gas over the tape while preparing the tape for sintering5214. In some embodiments, the step of advancing the tape 5212 furthercomprises horizontally advancing the tape through the station, and/ordirectly supporting the tape by a gas bearing and/or an underlyingsurface and moving the tape relative to that surface and/or relative tothe opening 5128.

Example of Binder Removal

Applicant has used a binder burn-out furnace similar to binder removalstation 34 to remove binder from green tape prior to sintering. In oneexample, the green tape was tape cast zirconia ceramic grains loadedwith polymer binder forming a ribbon of about 42 mm wide and about 25 μmthick. The green tape was feed through a horizontal six-hot-zone binderburnout furnace at 20 inches per minute. The binder burnout furnace wasset at 325° C. inlet to 475° C. outlet with 0 to 25° C. increasingdegree increments for the other four hot zones. About 7.5 liters perminute of air flow at temperatures 0 to 250° C. was also provided. Theair flow was divided between both sides of the binder burn-out furnace.The furnace was 36 inches long and had an 18-inch hot zone.

Sintering Station

Referring to FIG. 12 through FIG. 20, sintering station 38 is shown anddescribed in more detail. In general, following removal of bindermaterial from green tape 20 within binder removal station 34, unboundtape 36 moves into sintering station 38.

In at least one specific embodiment, sintering station 38 includes asintering furnace 100. Sintering furnace 100 includes an insulatedhousing 102. In general, insulated housing 102 includes a plurality ofinternal walls that define a channel 104 that extends through sinteringfurnace 100 between an entrance, shown as entrance opening 106, and anexit, shown as exit opening 108. Binder removal station 34 is locatedadjacent to entrance opening 106 such that green tape material 20 passesthrough binder removal station 34 producing unbound tape material 36 asdescribed above. Unbound tape material 36 passes into entrance opening106 and through channel 104. While within channel 104, heat generated bya heater (explained in more detail below, and above with regard todifferent types of heating elements) causes sintering of unbound tape 36to form sintered tape 40, and sintered tape 40 passes out through exitopening 108 for further processing or uptake as shown in FIG. 3.Depending on the temperature profile that unbound tape 36 is exposed toduring sintering, upon exiting sintering furnace 100, tape 40 may befully sintered or partially sintered. Whether tape 40 is partiallysintered or fully sintered, the porosity of tape 40 is less than theporosity of green tape 20 due to the sintering that occurs withinfurnace 100. Similarly, in some embodiments, the width of tape 40 isless than the width of green tape 20. In some such and yet otherembodiments, shrinkage of unbound tape 36 may be controlled duringsintering such that thickness, width and/or length of tape 40 is lessthan the thickness of green tape 20.

As can be seen in FIG. 12, and in contrast to typical discreet piecebased sintering systems, unbound tape 36 is a continuous length ofmaterial that extends completely through furnace 100. In thisarrangement, a single continuous length of unbound tape 36, extends intoentrance 106, through channel 104 and out of exit 108. As will beunderstood, because unbound tape 36 is continuous through furnace 100,its left edge, its right edge and its centerline (e.g., a longitudinalline located parallel to and equidistance from the left edge and theright edge) also or may also extend the entire distance through furnace100 between entrance 106 and exit 108. For reference, FIG. 14, shows theedges referenced above, as edges 130 and 132, after exiting sinteringfurnace 100. This relationship between the continuous tape 36 andfurnace 100 is believed to be unique to the roll-to-roll sinteringprocess discussed herein and is different from the physical arrangementof tunnel kiln processing for sintering in which discreet pieces ofmaterial move through a furnace supported by a setter board that movesthrough the furnace with the piece that is being sintered. For example,in some embodiments, the tape slides along and/or relative to asurface(s) (e.g., lower surface 126) through channel 104 of furnace 100,and is not carried on a setter or conveyor, which may reduce bonding toand adhesive wear of the tape associated with setters and static versusdynamic friction and adhesion.

As noted above, Applicant has found that a high level of horizontalityof channel 104 and/or of unbound tape 36 within channel 104 reduces theeffect of turbulent air flow on tape 36 during sintering. As shown inFIG. 12, channel 104, entrance 106, and exit 108 lie in a substantiallyhorizontal plane. In specific embodiments, the path defined through thecentral axes of channel 104, entrance 106, and exit 108 defines asubstantially horizontal plane and/or gradual arc or curve (e.g., havinga radius of curvature of at least 1 m). Similarly, in such embodiments,unbound tape 36 may also lie within a substantially horizontal planeand/or gradual arc or curve within channel 104 (e.g., upper surface 124and/or lower surface 126 of tape 36, shown in FIG. 13, lie in asubstantially horizontal plane). As used herein a substantiallyhorizontal plane of tape 36 and defined by channel 104, entrance 106,and exit 108 is one that forms angle of 10 degrees or less relative to ahorizontal reference plane. In other specific embodiments, channel 104,entrance 106, and exit 108 and/or tape 36 within channel 104 lie in aneven more horizontal plane, such as a plane forming an angle of 3degrees or less relative to a horizontal reference plane, and morespecifically at an angle of 1 degree or less relative to a horizontalreference plane. In other embodiments, the channel 104 is not sooriented, and the corresponding sintered tape may have indicia (e.g.,rolling surface mounds or bumps) associated with the “chimney effect” orirregular heating, such as if air flow through the channel 104 isturbulent.

To further control or limit turbulent air flow that the tape material ofsystem 10 is exposed to during traversal of system 10, binder removalstation 34 may be positioned relative to sintering station 38 in mannerthat maintains the tape material (e.g., green tape material 20 withinbinder removal station and unbound tape material 36 within sinteringstation) in a substantially horizontal position as tapes 20 and 36traverse binder removal station 34 and sintering station 38. In suchembodiments, similar to the horizontal positioning of sintering channel104, binder removal station 34 is or may be also oriented in asubstantially horizontal position, such as where openings 116, 118 arealigned to form a line therebetween that is within 10 degrees ofhorizontal.

In such embodiments, binder removal station 34 includes a binder burnout furnace 110. Binder burn out furnace 110 includes an insulatedhousing 112. In general, insulated housing 112 includes a plurality ofinternal walls that defines a channel 114 that extends through binderburnout furnace 110 between an entrance opening 116, and an exit opening118.

As shown in FIG. 12, referring to binder burn out furnace 110, channel114, entrance opening 116, and exit opening 118 lie in a substantiallyhorizontal plane. In specific embodiments, the path defined through thecentral axes of channel 114, entrance 116, and exit 118 defines asubstantially horizontal plane. Similarly, in such embodiments, greentape 20 may also lie within a substantially horizontal plane withinchannel 114. As used herein a substantially horizontal plane of greentape 20 and of channel 114, entrance opening 116, and exit opening 118is one that forms an angle of 10 degrees or less relative to ahorizontal reference plane. In other specific embodiments, channel 114,entrance opening 116, and exit opening 118 and/or green tape 20 withinchannel 114 lie in an even more horizontal plane, such as a planeforming an angle of 3 degrees or less relative to a horizontal referenceplane, and more specifically at an angle of 1 degree or less relative toa horizontal reference plane. In still other embodiments, these featuresmay not be so horizontally aligned.

In addition to maintaining horizontality of green tape 20 and unboundtape 36 within binder burnout furnace 110 and sintering furnace 100,respectively, binder burnout furnace 110 (also called binder removalstation) and sintering furnace 100 are aligned relative to each othersuch that unbound tape 36 maintains a horizontal position as unboundtape 36 transitions from binder burnout furnace 110 to sintering furnace100. Applicant has found that at this transition point, unbound tape 36is particularly susceptible to deformation or breakage due to variousforces (such as force caused by turbulent airflow) because with most ofthe organic binder removed, the unsintered inorganic grains of unboundtape 36 are held together by relatively weak forces (e.g., Van der Wallsforces, electrostatic interaction, a small amount of remaining organicbinder, frictional interaction/engagement between adjacent particles,low levels of inorganic carried in the binder, plasticizer, liquidvehicle, perhaps some particle-to-particle bonding etc.), and thus, evenrelatively small forces, such as those cause by turbulent airflowinteracting with unbound tape 36, can cause deformation or breakage.

Thus, as shown in FIG. 12, to limit turbulent airflow, channel 114 ofbinder burnout furnace 110 is aligned with channel 104 of sinteringfurnace 100 in the vertical direction. Following the tape path throughsintering furnace 100 and binder burnout furnace 110, green tape 20moves in the horizontal direction from the input roll (shown in FIG. 3)into binder burnout entrance 116, through binder burnout channel 114 andout of binder burnout exit 118. While within channel 114, heat generatedby the heater of furnace 110 chemically changes and/or removes at leasta portion of the organic binder material of green tape 20, called“burnout.” In addition, the relative positioning of binder burnoutfurnace 110 and sintering furnace 100 is such that unbound tape 36 movesinto sintering furnace 100 from binder burnout furnace 110 all whileremaining in a horizontal position or a generally horizontal position asdescribed above. Thus, the vertical alignment between channels 104 and114 allows unbound tape 36 to remain in the substantially the samehorizontal plane (i.e., without shifting up or down between furnaces 110and 100) as the tape material traverses both furnaces 100 and 110, atleast in some embodiments.

Applicant has determined that a benefit of horizontal binder removaland/or horizontal sintering becomes more important as the width of thetape material increases because wider tape materials are moresusceptible to airflow turbulence-based deformation. Thus, Applicantbelieves that the horizontal arrangement of sintering furnace 100 and/orbinder burnout furnace 110 allows for production of wider and/or longersintered tape materials without significant deformation or breakagebelieved not achievable using prior systems.

Referring to FIG. 13 and FIG. 14, in addition to horizontal positioningof binder burnout furnace 110, of the sintering furnace 100 and of thetape materials (e.g., green tape 20 and unbound tape 36) within thefurnaces, Applicant has also discovered that turbulent airflow can belimited by providing sintering channel 104 with a relatively low heightdimension (which in turn relates to a relatively low clearance relativeto unbound tape 36). Applicant has discovered that turbulent airflows,that may otherwise be experienced due to the very hot air within channel104, can be limited by decreasing the volume of the region within whichthermal gradients can develop and within which such thermal gradientscan cause air to move.

As shown in FIGS. 13 and 12, channel 104 is defined in part by ahorizontal, and generally upwardly facing surface 120 which defines atleast a portion of the lower surface of channel 104. Similarly, channel104 is also defined in part by a horizontal, and generally downwardlyfacing surface 122 which defines at least a portion of the upper surfaceof channel 104. A first gap, shown as G1, is the vertical distancebetween upwardly facing surface 120 and downwardly facing surface 122,and G2 is the vertical distance or clearance between downwardly facingsurface 122 and upper surface 124 of unbound tape 36.

As noted above, in various embodiments, G1 and G2 are relatively smallsuch that turbulent air flow is limited, but G1 and G2 should generallybe large enough that various processing steps (e.g., threading ofchannel 104 for example) are possible. In various embodiments, G2 isless than 0.5 inches (less than 12.7 mm), specifically is less than0.375 inches (less than 9.5 mm) and more specifically is 0.25 inches(about 6.35 mm). As will be understood, G1 is generally equal to G2 plusthe thickness T1 of unbound tape 36. Thus, in various embodiments,because T1 is relatively low, e.g., between 3 microns and 1 millimeter,G1 is less than 1 inch (less than 25.4 mm), specifically less than 0.75inches (less than 19 mm), and for thin tape materials may be less than0.5 inches (less than 12.7 mm), and for very thin tape materials may beless than 0.375 inches (less than 9.5 mm).

FIG. 14 shows exit 108 of sintering furnace 100 showing the smallclearance, G2, relative to tape 40 according to an exemplary embodiment.In various embodiments, G1 and G2 may represent the maximum gapdistances between the relevant surfaces and in another embodiment, G1and G2 may represent the average gap distances between the relevantsurfaces measures along the length of channel 104.

In specific embodiments, surface 120 and/or surface 122 are alsosubstantially horizontal surfaces (as described above) that extendbetween entrance 106 and exit 108 of furnace 100. In such embodiments,surfaces 120 and 122 therefore define a substantially horizontal channel104. In some specific embodiments, surfaces 120 and/or 122 may be flat,planar horizontal surfaces extending the entire distance betweenentrance 106 and exit 108 of furnace 100. In other specific embodiments,surfaces 120 and/or 122 may be gradually arcing or curving as describedabove, as may also be the case with the binder removal station. Inspecific embodiments, surfaces 120 and/or 122 are substantiallyhorizontal such that the surfaces form an angle less than 10 degrees,specifically less than 3 degrees and even more specifically less than 1degree relative to the horizontal reference plane.

As shown in FIG. 13, a lower surface 126 of unbound tape 36 is incontact with upwardly facing surface 120 such that lower surface 126 ofunbound tape 36 slides along or relative to upwardly facing surface 120,as unbound tape 36 advances through furnace 100. In particularembodiments, the sliding contact between lower surface 126 and upwardlyfacing surface 120 during sintering creates or may create variouslongitudinal features (e.g., longitudinally extending marks, troughs,ridges, etc.) formed in lower surface 126 but not on the upper surface124. Therefore, in specific embodiments, the surface features on lowersurface 126 are different from those of upper surface 124 which is notin contact with an opposing surface during sintering. In particular,this sliding contact is substantially different from the arrangement insome firing processes, such as tunnel kiln processes, in which a ceramicmaterial is placed on a setter board and both move together through thesintering furnace. In specific embodiments, surfaces 120 and 122 are orcomprise alumina, such as inner surfaces of an alumina tube that defineschannel 104.

In addition the positional arrangements and airflow control arrangementsdiscussed above, Applicant has also found that control of thetemperature profile through furnace 100, that unbound tape 36 is exposedto, is important to limit tape deformation or breakage, which Applicanthas discovered may occur if the temperate rise is too fast (e.g.,sintering rate is too fast or over too short a distance in the tape). Ingeneral referring to FIG. 15, furnace 100 may include a plurality ofindependently controlled heating elements 140 positioned to deliver heatto channel 104 in order to cause sintering of unbound tape 36 as tape 36traverses furnace 100. While the maximum and minimum sinteringtemperatures will vary at least in part based on the type of inorganicmaterial grains carried by tape 36, in general, heating elements 140 areconfigured to generate a temperature of at least 500 degrees C. along atleast a portion of channel 104. In some embodiments, for example forsintering ThO₂ (thoria) and/or TiO₂ (titania), channel 104 may be heatedto maximum temperatures above 3100 degrees C. There are some materials,e.g., carbides, tungsten, that have melting points above 3200 degrees,and in some such embodiments, the temperature range generated by heaters140 is between 500 degrees C. and a higher temperature, e.g., 3500degrees C., or 3600 degrees C. In specific embodiments, heating elements140 may be U-shaped molybdenum disilicide heating elements and/or otherheating elements disclosed herein.

In general, each heating element 140 may be under the control of acontrol system 142 which is configured (e.g., physically arranged,programmed, etc.) to independently control individual heating elements140 of the furnace 100 to generate a temperature profile along thelength of channel 104 to provide the desired level of sintering insintered tape 40, while limiting deformation during sintering. In someembodiments, control system 142 may be in communication with one or moretemperature sensors 144, which detects temperature within channel 104.In such embodiments, control system 142 may control heating elements 140based on an input signal received from sensor 144 such that a desiredtemperature profile is maintained during continuous sintering ofcontinuous unbound tape 36. In some embodiments, control system 142 mayalso receive input signals indicative of tape movement speed, position,shrinkage, and tension and control temperature and/or movement speedbased on these signals or other signals, which may be related to theseor other tape properties.

As will be demonstrated in relation to the sintering furnace examplesset forth below, Applicant has discovered that application of asintering temperature profile along the length of channel 104 is or maybe important to maintaining a low or controlled level of deformation inthe tape material during sintering. In particular, Applicant hasdiscovered that if the rise of temperature that unbound tape 36 isexposed to during sintering is too great (e.g., the slope of thetemperature profile is too steep), unacceptably high levels of stressare or may be formed within tape 36 as the material sinters and shrinks,which in turn results in out of plane deformation in tape 36, such asthat shown in FIG. 2. In particular, Applicant has discovered that bycontrolling stresses at edges 130 and 132 and/or along the centerline oftape 36 during sintering, deformation of tape 36 during sintering can becontrolled. A similar potentially deleterious effect on tape 36 may beexperienced if the transition from the heated portions of system 10 tothe room temperature portions of system 10 (e.g., upon exit from furnace100) occurs too sharply. With that said, technology of the presentapplication may be used to sinter tape without such temperature controlor profile, where the resulting new tape or other sintered articles mayhave such characteristic deformation or other defects.

Referring to FIG. 16 and FIG. 17, temperature profiles 160 and 170generated by heating elements 140 along the length of sintering channel104 is shown according to exemplary embodiments. Referring to FIG. 16,temperature profile 160 shows that the temperature within channel 104generally increases along the length of channel 104 in the processingdirection 14. Profile 160 includes at least three sections: a firstsection 162 representing the temperature within the region of channel104 adjacent to entrance opening 106; a second section 164 representingthe temperature along the majority (e.g., at least 50%, at least 75%,etc.) of the length of channel 104; and a third section 166 representingthe temperature within the region of channel 104 adjacent to exitopening 108.

As shown in FIG. 16, the average slope of first section 162 is greaterthan the average slope of second section 164 showing a relatively rapidincrease in temperature within channel 104 adjacent the entrance opening106. The average slope of second section 164 is relatively low (andlower than that of first section 162). The low average slope of secondsection 164 represents the gradual rise in temperature that tape 36experiences as it moves along most of the length of channel 104. As willbe discussed below, this gradual rise is selected to maintain stresseswithin tape 36 below determined thresholds that maintain deformationbelow the desired level. The average slope of third section 166 is anegative slope representing the cool down section within channel 104adjacent exit opening 108 which limits thermal shock experienced by tape36 upon exit from furnace 100.

In various embodiments, the gradual temperature rise represented by thelow slope of section 164 may be achieved by controlling the rate oftemperature increase along the length of channel 104. In variousembodiments, as represented by the x-axis in the plot of FIG. 16, thelength of channel 104 may be relatively large such as at least 1 meter,at least 50 inches, at least 60 inches or more. In the specificsintering furnace modeled and shown in FIG. 16, the heated channel 104is 64 inches.

In various embodiments, profile 160 is shaped to maintain an acceptablylow level of compressive stress within tape 36 during sintering suchthat undesirable deformation is avoided. Applicant has discovered thattape deformation, if not controlled as discussed herein, is a challengeparticularly for wide tape materials and high throughput sinteringsystems. In particular, wider tapes are more susceptible to this type ofdeformation, and in addition, width wise deformation makes or maywinding on uptake reel difficult or impossible. With that said, aspectsof the presently disclosed technology (e.g., carrier separation, tensioncontrol, binder removal, etc.) may be practiced and used to create newmaterials and products without the temperature profiles, such as whereresulting products are narrower and/or have defects or deformationcharacteristic of such processing.

Thus, in various embodiments, profile 160 is shaped such thatcompressive stress at the left edge 130 and/or right edge 132 of unboundtape 36 during sintering remains below an edge stress threshold and thatcompressive stress at a centerline of the unbound tape 36 duringsintering remains below a centerline stress threshold. In general, theedge stress threshold and the centerline stress threshold are defined asthe compressive stresses above which unbound tape 36 experiences out ofplane (length-width plane) deformation of greater than 1 mm duringsintering. Applicant has discovered that for at least some materials andtape widths, out of plane deformation can be limited to below 1 mmduring sintering by maintain the edge compressive stresses andcenterline compressive stresses below thresholds of 100 MPa,specifically 75 MPa and more specifically 60 MPa. In a specificembodiment, Applicant has discovered that for at least some materialsand tape widths, out of plane deformation can be limited to below 1 mmduring sintering by maintaining centerline compressive stresses belowthresholds of 100 MPa, specifically 75 MPa and more specifically 60 MPa,and by maintaining edge stresses below thresholds of 300 MPa,specifically 250 MPa and more specifically 200 MPa.

In a specific embodiment, the slope of sections 162 and 166 may becontrolled to provide for particularly low tape stresses on entry to andexit from furnace 100. In one such embodiment, control system 142 isconfigured to control the temperature profile within sections 162 and166 in combination with control of the speed of tape through furnace100. In such embodiments, this combination of controlling temperaturewithin sections 162 and 166, coupled with speed control, give a uniformsintering shrinkage (strain) and thus a low stress and low deformationwithin tape 36 during sintering.

Referring to FIG. 17, another exemplary temperature profile 170 is shownprojected along a view of channel 104. As shown, profile 170 shows anincrease to the maximum temperature at zone 172 over approximately atleast 75% of the total length of channel 104. In particular embodiments,sintering furnace 100 can be can be made of a high thermal conductivitymaterial (such as steel or high conductivity ceramic) to lowertemperature gradients in the cross web (tape/sheet) width direction. Asshown in FIG. 17, there is low or no temperature variance in the widthdirection. As will be generally understood, the temperature profile fora particular sintering system will be based on a number of factorsincluding the material type, inorganic particle size, particle density,particle size distribution, porosity, porosity size, porosity sizedistribution, the sintering atmosphere, the stress thresholds/allowabledeformation for the part as discussed above, length of the channel 104,throughput speed, etc. as well as desired outcome.

Referring to FIG. 18, another embodiment of sintering station 38 isshown according to an exemplary embodiment. In this embodiment,sintering station 38 includes two furnaces 180 and 182 positioned inseries with each other. In general, furnaces 180 and 182 aresubstantially the same as furnace 100 discussed above, except that, inat least some embodiments, the temperature profile of furnace 180 isdifferent than the temperature profile within furnace 182. In thisarrangement, unbound tape 36 enters entrance 106 of furnace 180. Withinfurnace 180, unbound tape 36 is partially sintered forming partiallysintered tape 184 which leaves furnace 180 through exit 108. Thenpartially sintered tape 184 enters second furnace 182 through entrance106, and additional sintering occurs along the length of channel 104 offurnace 182 such that sintered tape 40 exits furnace 182 through exit108 for reel uptake as discussed above.

In various embodiments, each furnace 180 and 182 includes a plurality ofindependently controllable heating elements such that a different andindependent temperature profile can be formed in each furnace 180 and182. In some embodiments, utilizing two thermally isolated furnaces,such as furnace 180 and 182, may provide more precise control of thetemperature profiles that the tape material is exposed to duringsintering, as compared to a single long furnace having the same channellength as the combined channel length of furnaces 180 and 182. In othercontemplated embodiments, the tape can be moved back through the samefurnace, but along a different path and/or exposed to a differenttemperature profile for additional sintering.

In addition, in some embodiments, application of differential tensionbetween furnace 180 and 182 may be desirable. In such embodiments, atension control system 186 is located along the sintering path definedby the channels 104 of furnaces 180 and 182. In specific embodiments,tension control system 186 is located between furnaces 180 and 182 andapplies tension to partially sintered tape 184 such that the tensionwith tape 184 within second furnace 182 is greater than the tension withunbound tape 36 within furnace 180. In various embodiments, increasingtension in the second sintering furnace may be desirable to provide forimproved flatness or deformation reduction during the final orsubsequent sintering of furnace 182. In addition, this increased tensionmay be suitable for application to partially sintered tape 184 becausethe partial sintering increases the tensile strength of tape 184 ascompared to the relatively low tensile strength of unbound tape 36within furnace 180.

Referring to FIG. 19, prophetic temperature profiles within furnaces 180and 182 are shown according to an exemplary embodiment. As shown in FIG.19, the heating elements of furnace 180 are controlled to generatetemperature profile 190, and the heating elements of furnace 182 arecontrolled to generate temperature profile 192. As will be noted, bothprofiles 190 and 192 have the same, low stress generating, gradualtemperature increase similar to that of temperature profile 160discussed above. However, profile 192 is located above profile 190(e.g., has a higher average temperature than profile 190) which causesthe additional, higher levels of sintering (e.g., additional shrinkage,additional decrease in porosity) that occurs as partially sintered tape184 traverses furnace 182.

Referring to FIG. 20, a high throughput sintering system 200 is shownaccording to an exemplary embodiment. In general, system 200 includestwo parallel systems 10, each sintering a tape material. System 200 maybe operated to increase the output of a single type of sintered tapematerial, similar to the arrangement in FIG. 18. Alternatively, eachsystem 10 of system 200 may output a different sintered tape material.In various embodiments, system 200 may include 3, 4, 5, etc. systems 10in parallel to further increase output of sintered tape material.

Sintering Station Examples and Models

Referring to FIG. 21 through FIG. 28, various sintering tests andsintering models are described demonstrating the sintering relationsdiscussed herein, such as the relation between temperature profile andshrinkage rate, the relation between the temperature profile and stresswith the tape material, the relationship between stress and tapedeformation, and the relationship between tape width and risk ofsintering deformation.

Physical Sintering Test Example 1

In one example, a horizontal furnace with an actively controlledmultiple zone binder burnout furnace was tested. In this test, a tapecast “green” zirconia ceramic ribbon (ceramic loaded with polymerbinder), 42 mm wide and about 25 microns thick, was fed through ahorizontal apparatus with the multi-zone binder burnout furnace (similarto furnace 38 and binder removal station 34 above) at 20 inches perminute. The binder burnout furnace was set at 325 degrees C. at theinlet to 475 degrees C. at the outlet with 0-25 increasing degree C.increments for the four central hot zones. Air flow at 7.5 liter perminute at a temperature range from about 0° C. to about 250° C. was alsoprovided, and the air flow was divided between both sides of the burnout furnace. The sintering furnace was 36 inches long and had an 18 inchlong hot zone. The tape was transported within the sintering furnace bysliding it over an alumina “D” tube, with a tension 20 grams and withthe furnace set at 1225° C. A resulting 10-20 feet of sintered zirconiatape was made and spooled on a take-up reel 3 inches in diameter.Sintering shrinkage across the width was about 12%.

Sintering Model 1

Referring to FIG. 21 and FIG. 22, sintering shrinkage of zirconia as afunction of time and temperature is shown. FIG. 21 shows a graph ofsintering shrinkage of a zirconia tape at various temperatures and timesat temperature. FIG. 22 shows a graph of curves generated by amathematical function of the sintering shrinkage of a zirconia tape atvarious temperatures and times at temperature.

To generate the data points shown in FIG. 21, a tape cast “green”zirconia ceramic ribbon (ceramic loaded with polymer binder) about 15 mmwide, 25 microns thick was “bisque” fired to 1200° C. at 8 inches perminute in the apparatus described in Physical Sintering Test Example 1,above. Bisque fired tapes produced in this manner were plunge fired in anarrow hot zone furnace for 30 seconds, 1 minute, 2 minutes, 3 minutesand 5 minutes at 1250° C., 1300° C., 1350° C., 1400° C., 1450° C., and1500° C. Sintering shrinkage was measured, and these data points areshown in FIG. 21.

From the sintering data, mathematical curves describing the sinteringshrinkage as a function of temperature and time were fitted andextrapolated to lower and intermediate temperatures than those actuallytested. This curve fitting and extrapolation is shown in FIG. 22. Basedon the testing and curve fitting shown in FIG. 21 and FIG. 22, therelation between sintering shrinkage, sintering time and temperature forzirconia was determined. Applicant believes this information can be usedto develop sintering temperature profiles for zirconia to achieve adesired shrinkage rate and to reduce stress below the deformationthresholds as discussed above.

In one specific embodiment, this data was used to model the 64 inchsintering furnace and temperature profile shown in FIG. 16. As shown inFIG. 16, the thermal gradient/profile 160 started at 1250° C. and endedat 1450° C. The modeled temperature increased from 1250° C. to 1300° C.from 0 to 8 inches into the furnace, was increased from 1300° C. to1312.5° C. from 8 to 16 inches, increased from 1312.5 to 1325° C. from16 to 24 inches, was maintained at 1325° C. from 24 to 32 inches,increased from 1325 to 1375° C. from 32 to 40 inches, was increased at1375° C. to 1400° C. from 40 to 48 inches, increased from 1400 to 1450°C. from 48 to 56 inches, was maintained at 1450° C. from 56 to 64inches, then cooled to below 1000° C. after 64 inches.

Shrinkage was modeled as a function of tape transport speed. As shown inFIG. 16, the model showed that a faster transport speed, 20 inches perminute (ipm), gave more uniform sintering shrinkage over the length ofthe hot zone. Thus, this modeling demonstrates that uniform shrinkageover longer lengths is desirable because the shorter the distance overwhich the sintering strain/shrinkage occurs, the larger the stress inthe tape and the greater propensity of buckling, and out of planeplastic deformation.

Sintering Model 2

Referring to FIGS. 23 and 16, sinter stress was modeled by finiteelement analysis (FEA) and a closed form (CF) solution. As demonstratedin FIG. 23 and FIG. 24, as the tape being sintered gets wider, extremesintering stress of greater than −1000 MPa are calculated for 100 mmwide stationary tapes (single hot zone), for 100 mm wide tapes wherethere are only two hot zones and for tape transported at 8 and 16 inchesper minute. In contrast, when 9 hot zones are used with 2 sinteringpasses (equivalent to 18 hot zones in a single pass), edge stresses lessthan about −200 MPa were modeled for 150 mm wide sheet. In the singleand 4 hot zone tests, each hot zone was modeled having a length of 450mm (18 inches) with the furnace being 900 mm (36 inches) and thus, inthese two modeling examples additional hot zones equates to a longer hotzone. For example, the 1 zone, 2 pass hot zone generally equates to atotal 900 mm long (36 inches) hot zone. However, for a 9 zone, 2 passhot zone is equivalent to a total 3660 mm (144 inch) (length) hot zone.Thus, FIG. 23 and FIG. 24 demonstrate that wider and wider tapes (e.g.,greater than 50 mm, 100 mm, 150 mm, 200 mm, 250 mm, etc.) can beaccommodated by controlling the number of hot zones (e.g., the totallength of the sintering hot zone), the temperature profile the tape isexposed to, and the movement rate of the tape through the hot zone,sintering stress can be maintained at levels low enough to avoidgeneration of deformation, buckling, or breakage.

Sintering Model 3

FIG. 25 and FIG. 26 show a model of a bisque zirconia tape (i.e., apartially sintered tape) that is passed twice through a single hot zonewith steep temperature gradients. The hot zones were set at 1250° C. forthe first pass and then 1400° C. for the second pass. Tape transportspeeds of 8 and 16 inches per minute were inputs. The tape was modeledto be 20 microns thick and 15 mm and 40 mm wide. FIG. 25 shows shrinkagethrough the hot zones, and FIG. 26 shows that substantial compressivestress, greater than 90 MPa (for 40 mm wide tape at 8 ipm) is generatedin the tape and greater than 120 MPa (for 40 mm wide tape at 16 ipm) dueto the rapid sintering strain. This is believed to lead to buckling andout of plane deformation for tape having these widths and thicknesses.

Sintering Model 4

FIG. 27 and FIG. 28 show the results when the model uses a multi-zonefurnace with ten hot zones and two passes with the second pass set athigher temperatures than the first pass. The modeled stress drops by anorder of magnitude for both tape transport speed and tape widths ascompared to the stress shown in FIG. 26. This lower stress is believedto lead to much flatter tape, e.g., less deformation. Further, thismodel demonstrates the effect of a controlled sintering temperatureprofile or gradual rise of temperature during sintering on stress andconsequently deformation.

Physical Sintering Test Example 2

In another test example, a tape cast “green” zirconia ceramic ribbon(ceramic loaded with polymer binder) about 25 microns thick and 15 cmwide was made with a vertically-oriented sintering apparatus at asintering temperature of 1100° C. About 50 feet was made and spooled ona take-up reel 3 inches in diameter. Bisque sintering shrinkage widthwas about 10%

This 1100° C. “bisque” tape was then passed through a horizontalsintering furnace, substantially the same as that shown in FIG. 12 atspeeds of about 3, 10, 20, 30, 60 and 75 inches per minute with thefurnace set at 1550° C. A resulting length of 40 feet of sintered tapewas made and spooled on a take-up reel of 3 inches in diameter. Tensionon the tape during sintering was in the range of 10 grams, even at 75inches per minute with the tape in the hot zone for less than about 15seconds, a porosity of less than 20% was achieved. Slower speeds gavedenser material. Thus this test demonstrates that longer sinteringfurnaces lead to higher density/lower porosity in the sintered tape andalso that higher temperature lead to higher density/lower porosity inthe sintered tape.

Physical Sintering Test Example 3

In another test example, a tape cast “green” alumina ceramic ribbon(ceramic loaded with polymer binder) about 50 microns thick was fedthrough a system substantially the same as that shown in FIG. 3, at 4-6inches per minute. The binder burnout furnace was set at 325° C. inletto 475° C. outlet with 0-25 increasing degree increments for the fourcentral hot zones. A 5-7.5 liter per minute air flow at 0-250° C. wasused. The sintering furnace was 36 inches long with an 18 inch hot zoneset at 1300° C. The green tape was passed through the 18 inch sinteringhot zone at 1300° C., producing a partially sintered, “bisque” tape. Thewidth of the partially sintered tape was 7% less than the width of thegreen tape.

The 1300° C. “bisque” tape was then passed through the sintering furnacea second time at 2 inches per minute with the sintering furnace set at1550° C., producing about 20 feet of fully sintered alumina tape. Thetape was spooled on a take-up reel 6 inches in diameter. Tension on thetape was about 100 grams during sintering, and sintering shrinkage widthfor the second pass was about 15%. After sintering, the tape wastranslucent, almost transparent. When set on a written document youcould read through it. The grain size was below about 2 microns and thematerial had less than about 1% porosity.

Test Example 4

In another test example, a tape cast “green” zirconia ceramic ribbon(ceramic loaded with polymer binder) about 50 microns thick was fedthrough a system substantially the same as that shown in FIG. 3 at 6inches per minute. The binder burnout furnace was set at 300-475 degrees° C., with −7.5 liters per minute of air flow at 200-250° C. Thesintering furnace was 36 inches long with an 18 inch hot zone.Temperature gradients were 25° C. to 1225° C. in less than 9 inches and1000° C. to 1225° C. over 3-4 inches. Two D tubes spaced apart by about⅜ inch were used to restrict air circulation and lessen the temperaturegradients. Tension in the tape was 20-60 grams, and the sinteringfurnace was set at 1225° C. A resulting length of 50 feet of sinteredzirconia was made and spooled on a take-up reel of 3 inches in diameter.Sintering shrinkage width was about 12%.

To physically model a furnace with a shallow temperature gradient, the1225° C. sintered “bisque tape” was passed through the single zonefurnace three times at progressively higher temperatures, which reducesthe sintering shrinkage for each pass, reducing the out of planedeformation. Specifically, the 1225° C. “bisque” tape was then passedthrough the furnace a second time at 6 inches per minute with thefurnace set at 1325° C. Via this process 45 feet of sintered zirconiatape was made and spooled on a take-up reel 3 inches in diameter.Tension on the tape during sintering was 100-250 grams, and sinteringshrinkage width for this pass was 5-6%.

The 1325° C. tape was then passed through the furnace a third time at 6inches per minute with the furnace set at 1425° C. About 40 feet ofsintered zirconia tape was made and spooled on a take-up reel 3 inchesin diameter. Tension on the tape during sintering was 100-250 grams, andsintering shrinkage width for this pass was 5-6%. After the 1425° C.pass the tape was translucent, almost transparent. When set on a writtendocument you could read through it.

The 1425° C. tape was then passed through the furnace a fourth time at3-6 inches per minute with the furnace set at 1550° C. A few feet of1550° C. sintered tape was made and spooled on a take-up reel 3 inchesin diameter. Tension on the tape during sintering was 100-300 grams andsintering shrinkage (width) for this pass was 0-2%.

Sintered Article

Embodiments of the sintered articles formed using the systems andprocesses described herein will now be described. The sintered articlesmay be provided in the form of a sintered tape (i.e., a continuoussintered article) or a discrete sintered article(s). Unless otherwiseindicated, the term “sintered article” is intended to refer to both acontinuous sintered article and a discrete sintered article(s). Inaddition, “sintered” refers to both partially sintered articles andfully sintered articles. In one aspect, embodiments of the sinteredarticle comprise dimensions not previously achievable. In one or moreembodiments, the sintered article also exhibit uniformity of certainproperties along these dimensions. According to another aspect,embodiments of the sintered article exhibits a flattenability thatindicates the sintered article can be flattened or subjected toflattening without imparting significant stress in the sintered articleand thus can be used successfully in downstream processes. Anotheraspect pertains to embodiments of a rolled sintered article, and yetanother aspect pertains to embodiments of a plurality of discretesintered articles. Still other aspects include new compositions ofmaterials, or compositions with new microstructures, such as in terms ofunique grain boundaries, for example.

Referring to FIG. 29, a sintered article 1000 according to one or moreembodiments includes a first major surface 1010, a second major surface1020 opposing the first major surface, and a body 1030 extending betweenthe first and second surfaces. The body 1030 has a thickness (t) definedas a distance between the first major surface and the second majorsurface, a width (W) defined as a first dimension of one of the first orsecond surfaces orthogonal to the thickness, and a length (L) defined asa second dimension of one of the first or second surfaces orthogonal toboth the thickness and the width. In one or more embodiments, thesintered article includes opposing minor surfaces 1040 that define thewidth (W). In specific embodiments, sintered article 1000, as describedherein, is an example of sintered tape 40 produced using system 10,albeit some tapes of the present technology may be longer than the tapeshown in FIG. 29.

In one or more embodiments, the sintered article is a continuoussintered article having a width of about 5 mm or greater, a thickness ina range from about 3 μm to about 1 mm, and a length in a range of about300 cm or greater. In other embodiments, the width is less than 5 mm, asdescribed above.

In one or more embodiments, the sintered article has a width in a rangefrom about 5 mm to about 200 mm, from about 6 mm to about 200 mm, fromabout 8 mm to about 200 mm, from about 10 mm to about 200 mm, from about12 mm to about 200 mm, from about 14 mm to about 200 mm, from about 15mm to about 200 mm, from about 17 mm to about 200 mm, from about 18 mmto about 200 mm, from about 20 mm to about 200 mm, from about 22 mm toabout 200 mm, from about 24 mm to about 200 mm, from about 25 mm toabout 200 mm, from about 30 mm to about 200 mm, from about 40 mm toabout 200 mm, from about 50 mm to about 200 mm, from about 60 mm toabout 200 mm, from about 70 mm to about 200 mm, from about 80 mm toabout 200 mm, from about 90 mm to about 200 mm, from about 100 mm toabout 200 mm, from about 5 mm to about 150 mm, from about 5 mm to about125 mm, from about 5 mm to about 100 mm, from about 5 mm to about 75 mm,from about 5 mm to about 50 mm, from about 5 mm to about 40 mm, fromabout 5 mm to about 30 mm, from about 5 mm to about 20 mm, or from about5 mm to about 10 mm.

In some embodiments, the sintered article has a width W of at least 0.5mm, such as at least 1 mm, such as at least 2 mm, such as at least 5 mm,such as at least 8 mm, such as at least 10 mm, such as at least 15 mm,such as at least 20 mm, such as at least 30 mm, such as at least 50 mm,such as at least 75 mm, such as at least 10 cm, such as at least 15 cm,such as at least 20 cm, and/or no more than 2 m, such as no more than 1m, such as no more than 50 cm, such as no more than 30 cm. In otherembodiments, the sintered article has a different width W.

In one or more embodiments, the sintered article has a thickness (t) ina range from about 3 μm to about 1 mm, from about 4 μm to about 1 mm,from about 5 μm to about 1 mm, from about 6 μm to about 1 mm, from about7 μm to about 1 mm, from about 8 μm to about 1 mm, from about 9 μm toabout 1 mm, from about 10 μm to about 1 mm, from about 11 μm to about 1mm, from about 12 μm to about 1 mm, from about 13 μm to about 1 mm, fromabout 14 μm to about 1 mm, from about 15 μm to about 1 mm, from about 20μm to about 1 mm, from about 25 μm to about 1 mm, from about 30 μm toabout 1 mm, from about 35 μm to about 1 mm, from about 40 μm to about 1mm, from about 45 μm to about 1 mm, from about 50 μm to about 1 mm, fromabout 100 μm to about 1 mm, from about 200 μm to about 1 mm, from about300 μm to about 1 mm, from about 400 μm to about 1 mm, from about 500 μmto about 1 mm, from about 3 μm to about 900 μm, from about 3 μm to about800 μm, from about 3 μm to about 700 μm, from about 3 μm to about 600μm, from about 3 μm to about 500 μm, from about 3 μm to about 400 μm,from about 3 μm to about 300 μm, from about 3 μm to about 200 μm, fromabout 3 μm to about 100 μm, from about 3 μm to about 90 μm, from about 3μm to about 80 μm, from about 3 μm to about 70 μm, from about 3 μm toabout 60 μm, from about 3 μm to about 50 μm, from about 3 μm to about 45μm, from about 3 μm to about 40 μm, from about 3 μm to about 35 μm, fromabout 3 μm to about 30 μm, or from about 3 μm to about 30 μm.

In some embodiments, the sintered article has a thickness t of at least3 μm, such as at least 5 μm, such as at least 10 μm, such as at least 15μm, such as at least 20 μm, such as at least 25 μm, such as at least 0.5mm, such as at least 1 mm, and/or no more than 5 mm, such as no morethan 3 mm, such as no more than 1 mm, such as no more than 500 μm, suchas no more than 300 μm, such as no more than 100 μm. In otherembodiments, the sintered article has a different thickness t.

In one or more embodiments, the sintered article is continuous and has alength L in a range from about 300 cm to about 500 m, from about 300 cmto about 400 m, from about 300 cm to about 200 m, from about 300 cm toabout 100 m, from about 300 cm to about 50 m, from about 300 cm to about25 m, from about 300 cm to about 20 m, from about 350 cm to about 500 m,from about 400 cm to about 500 m, from about 450 cm to about 500 m, fromabout 500 cm to about 500 m, from about 550 cm to about 500 m, fromabout 600 cm to about 500 m, from about 700 cm to about 500 m, fromabout 800 cm to about 500 m, from about 900 cm to about 500 m, fromabout 1 m to about 500 m, from about 5 m to about 500 m, from about 10 mto about 500 m, from about 20 m to about 500 m, from about 30 m to about500 m, from about 40 m to about 500 m, from about 50 m to about 500 m,from about 75 m to about 500 m, from about 100 m to about 500 m, fromabout 200 m to about 500 m, or from about 250 m to about 500 m.

In some embodiments, the sintered article has a continuous, unbrokenlength L of at least 5 mm, such as at least 25 mm, such as at least 1cm, such as at least 15 cm, such as at least 50 cm, such as at least 1m, such as at least 5 m, such as at least 10 m, and/or no more than 5km, such as no more than 3 km, such as no more than 1 km, such as nomore than 500 m, such as no more than 300 m, such as no more than 100 m.In other embodiments, the sintered article has a different length L.Such continuous long lengths, particularly of materials and qualitiesdisclosed herein, may be surprising to those of skill in the art withouttechnologies disclosed herein, such as the controlled separation,tension control, sintering zones, binder removal techniques, etc.

In one or more embodiments, the body of the sintered article includes asintered inorganic material. In one or more embodiments, the inorganicmaterial includes an interface having a major interface dimension ofless than about 1 mm. As used herein, the term “interface” when usedwith respect to the inorganic material is defined as including either achemical inhomogeneity or a crystal structure inhomogeneity or both achemical inhomogeneity and a crystal structure inhomogeneity.

Exemplary inorganic materials include ceramic materials, glass ceramicmaterials and the like. In some embodiments, the inorganic material mayinclude any one or more of a piezoelectric material, a thermoelectricmaterial, a pyroelectric material, a variable resistance material, or anoptoelectric material. Specific examples of inorganic materials includezirconia (e.g., yttria-stabilized zirconia), alumina, spinel, garnet,lithium lanthanum zirconium oxide (LLZO), cordierite, mullite,perovskite, pyrochlore, silicon carbide, silicon nitride, boron carbide,sodium bismuth titanate, barium titanate, titanium diboride, siliconalumina nitride, aluminum oxynitride, or a reactive cerammedglass-ceramic (a glass ceramic formed by a combination of chemicalreaction and devitrification, which includes an in situ reaction betweena glass frit and a reactant powder(s)).

In one or more embodiments, the sintered article exhibits compositionaluniformity across a specific area. In one or more specific embodiments,the sintered article comprises at least 10 square cm of area along thelength that has a composition (i.e., relative amounts of chemicals inweight percent (%)) wherein at least one constituent of the compositionvaries by less than about 3 weight % (e.g., about 2.5 weight % or less,about 2 weight % or less, about 1.5 weight % or less, about 1 weight %or less, or about 0.5 weight % or less), across that area. For example,when the inorganic material comprises alumina, the amount of aluminummay vary by less than about 3 weight % (e.g., about 2.5 weight % orless, about 2 weight % or less, about 1.5 weight % or less, about 1weight % or less, or about 0.5 weight % or less), across the at least 10square cm of area. Such compositional uniformity may be attributed atleast in part to new, unique processes, as disclosed herein, such as thefurnace heat zones with individually controlled elements, careful andgentle handling of green tape, steady state of the continuous tapeprocessing, etc. In other embodiments, new and inventive tapes or otherproducts of at least some technology disclosed herein may not have suchcompositional uniformity.

In one or more embodiments, the sintered article exhibits crystallinestructure uniformity across a specific area. In one or more specificembodiments, the sintered article includes at least 10 square cm of areaalong the length that has a crystalline structure with at least onephase having a weight % that varies by less than about 5 percentagepoints, across that area. For illustration only, the sintered articlemay include at least one phase that constitutes 20 weight % of thesintered article and the amount of this phase is within the range fromabout 15 weight % to about 25 weight % across the at least 10 square cmof area. In one or more embodiments, the sintered article includes atleast 10 square cm of area along the length that has a crystallinestructure with at least one phase having a weight % that varies by lessthan about 4.5 percentage points, less than about 4 percentage points,less than about 3.5 percentage points, less than about 3 percentagepoints, less than about 2.5 percentage points, less than about 2percentage points, less than about 1.5 percentage points, less thanabout 1 percentage point, or less than about 0.5 percentage points,across that area. Such crystalline structure uniformity may beattributed at least in part to new, unique processes, as disclosedherein, such as the furnace heat zones with individually controlledelements, careful and gentle handling of green tape, steady state of thecontinuous tape processing, etc. In other embodiments, new and inventivetapes or other products of at least some technology disclosed herein maynot have such crystalline structure uniformity.

In one or more embodiments, the sintered article exhibits a porosityuniformity across a specific area. In one or more specific embodiments,the sintered article comprises at least 10 square cm of area along thelength that has a porosity varies by less than about 20%. As usedherein, the term “porosity” is described as a percent by volume (e.g.,at least 10% by volume, or at least 30% by volume), where the “porosity”refers to the portions of the volume of the sintered article unoccupiedby the inorganic material. Accordingly, in one example, the sinteredarticle has a porosity of 10% by volume and this porosity is within arange from about greater than 8% by volume to less than about 12% byvolume across the at least 10 square cm of area. In one or more specificembodiments, the sintered article comprises at least 10 square cm ofarea along the length that has a porosity varies by 18% or less, 16% orless, 15% or less, 14% or less, 12% or less, 10% or less, 8% or less, 6%or less, 5% or less, 4% or less or about 2% or less, across that area.Such porosity uniformity may be attributed at least in part to new,unique processes, as disclosed herein, such as the furnace heat zoneswith individually controlled elements, careful and gentle handling ofgreen tape, steady state of the continuous tape processing, etc. Inother embodiments, new and inventive tapes or other products of at leastsome technology disclosed herein may not have such porosity uniformity.

In one or more embodiments, the sintered article exhibits a granularprofile, such as when viewed under a microscope, as shown in the digitalimage of FIG. 30A for an example of such a granular profile structure,and conceptually shown in the side view of FIG. 30B, that includesgrains 1034 protruding generally outward from the body 1030 with aheight H (e.g., average height) of at least 25 nanometers (nm) and/or nomore than 150 micrometers (μm) relative to recessed portions of thesurface at boundaries 1032 between the grains 1034. In one or moreembodiments, the height H in a range from about 25 nm to about 125 μm,from about 25 nm to about 100 μm, from about 25 nm to about 75 μm, fromabout 25 nm to about 50 μm, from about 50 nm to about 150 μm, from about75 nm to about 150 μm, from about 100 nm to about 150 μm, or from about125 nm to about 150 μm. In one or more embodiments, the height H in arange from about 25 nm to about 125 nm, from about 25 nm to about 100nm, from about 25 nm to about 75 nm, from about 25 nm to about 50 nm,from about 50 nm to about 150 nm, from about 75 nm to about 150 nm, fromabout 100 nm to about 150 nm, or from about 125 nm to about 150 nm. Inother embodiments, the height H may be otherwise sized. In still otherembodiments, processing conditions (e.g., time, temperature) may be suchthat the sintered material has essentially zero height H. In someembodiments, for materials and manufacturing disclosed herein, products(e.g., tape) include a height H of grains of at least 25 nm, such as atleast 50 nm, such as at least 75 nm, such as at least 100 nm, such as atleast 125 nm, such as at least 150 nm, and/or no more than 200 μm, suchas no more than 150 μm, such as no more than 100 μm, such as no morethan 75 μm, such as no more than 50 μm. Size and shape of suchmicrostructure may be controlled using technology disclosed herein, suchas rate of conveyance through the furnace, temperature(s) andtemperature profile of the furnace, composition, particle/grain size anddensity of inorganic material in the green tape, and other factors asdisclosed herein.

The granular profile is or may be an indicator of the process ofmanufacturing used to form the sintered article 1000. In particular, thegranular profile is or may be an indicator that the article 1000 wassintered as a thin continuous article (i.e., as a sheet or tape), asopposed to being cut from a boule, and that the respective surface 1010,1020 has not been substantially polished. Additionally, compared topolished surfaces, the granular profile may provide benefits to thesintered article 1000 in some applications, such as scattering light fora backlight unit of a display, increasing surface area for greateradhesion of a coating or for culture growth. In contemplatedembodiments, the surfaces 1010, 1020 have a roughness from about 10 nmto about 1000 nm across a distance of 10 mm in one dimension along thelength of the sintered article, such as from about 15 nm to about 800nm. In contemplated embodiments, either or both of the surfaces 1010,1020 have a roughness of from about 1 nm to about 10 μm over a distanceof 1 cm along a single axis.

In one or more embodiments, the one or both surfaces 1010, 1020 may bepolished, where grain boundary grooves and grain asperities (orhillocks) are generally removed due to the polishing. In contemplatedembodiments, sintered articles 1000 manufactured according to theprocesses disclosed herein may be polished, with a surface similar tothat shown in FIGS. 31A-31B for example; depending upon, for example,the particular intended use of the article. For example, use of thesintered article 1000 as a substrate may not require an extremely smoothsurface, and the unpolished surface of FIGS. 30A-30B may be sufficient;whereas use of the article as a mirror or as a lens may requirepolishing as shown in FIG. 31A-31B. However, as disclosed herein,polishing may be difficult for particularly thin articles or those thatare thin with large surface areas. As indicated, substrates disclosedherein may also receive coatings which may change surface qualities,such as smoothness.

Without being bound by theory, it is believed that sheets of sinteredceramic or other materials cut from boules may not have readilyidentifiable grain boundaries present on surfaces thereon, in contrastto the article of FIGS. 30A-30B. Without being by theory, boule-cutarticles may typically be polished to correct rough surfaces from thecutting, such as with grooves from abrasion; however surface polishingmay be particularly difficult or cumbersome for very thin articles ofsintered ceramic or other materials, with the degree of difficultyincreasing as such articles are thinner and the surface areas of sucharticles are larger. However, sintered articles manufactured accordingto the presently disclosed technology may be less constrained by suchlimitations because articles manufactured according to the presenttechnology may be continuously manufactured in long lengths of tape.Further, dimensions of furnace systems, as disclosed herein, may bescaled to accommodate and sinter wider articles as described herein.

In some embodiments, such as where the sintered article 1000 is in theform of a sheet or tape, the surface consistency is such that either oneor both of the first and second surfaces 1010, 1020 have few surfacedefects. In this context, surface defects are abrasions and/or adhesionshaving a dimension along the respective surface of at least 15 μm, 10μm, and/or 5 μm. In one or more embodiments, one or both the first majorsurface 1010 and second major surface 1020 have fewer than 15, 10,and/or 5 surface defects having a dimension greater than 15 μm, 10 μm,and/or 5 μm per square centimeter. In one example, one or both the firstmajor surface 1010 and second major surface 1020 have fewer than 3 orfewer than 1 such surface defects on average per square centimeter. Inone or more embodiments, one of or both the first major surface and thesecond major surface have at least ten square centimeters of area havingfewer than one hundred surface defects from adhesion or abrasion with adimension greater than 5 μm. Alternatively or additionally, one of thefirst and major surface has at least ten square centimeters of areahaving fewer than one hundred surface defects from adhesion or abrasionwith a dimension greater than 5 μm, while the other of the first majorsurface and the second major surface comprises surface defects fromadhesion or abrasions with a dimension of greater than 5 μm.Accordingly, sintered articles manufactured according to inventivetechnologies disclosed herein may have relatively high and consistentsurface quality. Applicant believes that the high and consistent surfacequality of the sintered article 1000 facilitates increased strength ofthe article 1000 by reducing sites for stress concentrations and/orcrack initiations.

The sintered article may be described as having a flatness in a rangefrom about 0.1 μm (100 nm) to about 50 μm over a distance of 1 cm alonga single axis (e.g., such as along the length or the width of thesintered article). In some embodiments, the flatness may be in a rangefrom about 0.2 μm to about 50 μm, from about 0.4 μm to about 50 μm, fromabout 0.5 μm to about 50 μm, from about 0.6 μm to about 50 μm, fromabout 0.8 μm to about 50 μm, from about 1 μm to about 50 μm, from about2 μm to about 50 μm, from about 5 μm to about 50 μm, from about 10 μm toabout 50 μm, from about 20 μm to about 50 μm, from about 25 μm to about50 μm, from about 30 μm to about 50 μm, from about 0.1 μm to about 45μm, from about 0.1 μm to about 40 μm, from about 0.1 μm to about 35 μm,from about 0.1 μm to about 30 μm, from about 0.1 μm to about 25 μm, fromabout 0.1 μm to about 20 μm, from about 0.1 μm to about 15 μm, fromabout 0.1 μm to about 10 μm, from about 0.1 μm to about 5 μm, or fromabout 0.1 μm to about 1 μm. Such flatness, in combination with thesurface quality, surface consistency, large area, thin thickness, and/ormaterial properties of materials disclosed herein, may allow sheets,substrates, sintered tapes, articles, etc. to be particularly useful forvarious applications, such as tough cover sheets for displays,high-temperature substrates, flexible separators, and otherapplications. With that said, embodiments may not have such flatness.Flatness is measured with a respective national standard (e.g. ASTMA1030).

In one or more embodiments, the sintered article exhibits a striatedprofile along the width dimension as shown in FIG. 32. In one or moreembodiments, the body 1030 has a striated profile with a thickness thatis substantially constant along the width. For example, the thicknessalong the entire width is in a range from about 0.9t to about 1.1t(e.g., from about 0.95t to about 1.1t, from about 0.1t to about 1.1t,from about 0.105t to about 1.1t, from about 0.9t to about 1.05t, fromabout 0.9t to about t, or from about 0.9t to about 0.95t), where t isthe thickness values disclosed herein. As shown in FIG. 32, the striatedprofile includes two or more undulations along the width. As usedherein, undulations mean a full period. In some embodiments, thestriated profile includes 3 or more undulations, 4 or more undulations,5 or more undulations or 10 or more undulations along the entire width,with the upper limit of undulations being about less than about 20undulations along the entire width. In one or more embodiments, thestriations may be measured in terms of optical distortion. In one ormore embodiments, the sintered article may be placed in proximity to azebra board that consists of a white board with straight black stripesdisposed diagonally across the board. When viewing the zebra boardthrough the sintered article, distortions in the black stripes may bevisually detected and measured using methods and tools known in the art.In one example, the distortions may be measured according to ASTM C1048. In other embodiments, such as with polished or otherwise formedarticles disclosed herein, there may be fewer or no distortions. Instill other embodiments, distortions may be greater in quantity and/ormagnitude.

In one or more embodiments, the sintered article may be planar. In oneor more embodiments, a portion of the sintered article or a discretesintered article (as will be described herein) may have a have athree-dimensional shape. For example, in one or more embodiments, aportion of the sintered article or a discrete sintered article may havea saddle shape (which has a convex shape along the width and a concaveshape along the length, or a concave shape along the width and a convexshape along the length). In one or more embodiments, a portion of thesintered article or a discrete sintered article may have a c-shape(which has a single concave shape along the length). In one or moreembodiments, the shape magnitude (which means the maximum height of theportion of the sintered article or a discrete sintered article measuredfrom the plane on which it is disposed) is less than about 0.75 mm(e.g., about 0.7 mm or less, 0.65 mm or less, 0.6 mm or less, 0.55 mm orless, 0.5 mm or less, 0.45 mm or less, 0.4 mm or less, 0.35 mm or less,0.3 mm or less, 0.25 mm or less, 0.2 mm or less, 0.15 mm or less, or 0.1mm or less).

According to another aspect, the embodiments of the sintered article maybe described in terms of flattenability or being flattenable instandard, room temperature (at 23° C.) conditions, without heating thesintered article near melting or sintering temperature to soften thearticle for flattening. In some embodiments, a portion of the sinteredarticle is flattenable. A portion of the sintered article that isflattenable may have a length of about 10 cm or less. In someembodiments, the sintered article may have dimensions otherwisedescribed herein (e.g., width is about 5 mm or greater, the thickness isin a range from about 3 μm to about 1 mm, and the length is about 300 cmor greater), with the portion of the sintered article that isflattenable having a length of 10 cm or less. In some embodiments, forinstance where the sintered article is a discrete sintered article, theentire sintered article is flattenable.

As used herein, flattenability is determined by flattening the sinteredarticle by pinching the sintered article (or portion of the sinteredarticle) between two rigid parallel surfaces, or by applying surfacepressure on a first major surface 1010 of the sintered article (orportion of the sintered article) against a rigid surface to flatten thesintered article (or portion of the sintered article) along a planarflattening plane. The measure of flattenability may be expressed as theforce required to pinch the sintered article (or portion of the sinteredarticle) flat to within a distance of 0.05 mm, 0.01 mm or 0.001 mm fromthe flattening plane, when the sintered article (or portion of thesintered article) is pinched between two rigid parallel surfaces. Themeasure of flattenability may alternatively be expressed as the surfacepressure applied to a first major surface 1010 to push the sinteredarticle (or portion of the sintered article) flat to within a distanceof 0.001 mm from the flattening plane, when the sintered article (orportion of the sintered article) is pushed against a rigid surface. Themeasure of flattenability may be expressed as the absolute maximum inplane surface stress (compressive or tensile) on the sintered article(or portion of the sintered article) when the sintered article (orportion of the sintered article) is flattened to within a distance of0.05 mm, 0.01 mm or 0.001 mm from the flattening plane using eitherflattening method (i.e., pinching between two rigid parallel surfaces oragainst a rigid surface). This stress may be determined using the thinplate bend bending equation, σ_(x)=Et/2R(1−ν²).

The thin plate bend stress equation is derived from the equationσ_(x)=[E/(1−ν²)]·(ε_(x)+νε_(y)), where E is elastic modulus, ν isPoisson's ratio and ε_(x) and ε_(y) are strain in the respectivedirections. With a thick beam, where deflection is much less than thebeam thickness, ε_(x) is proportional to thickness squared. However,when the beam thickness is significantly less than the bend radius(e.g., the sintered article may have a thickness t of about 20 μm and isbent to a bend radius of a millimeter magnitude), ε_(y)=0 is applicable.As illustrated in FIG. 33, it is assumed that the thin plate (orsintered article) is bent into a section of a circle where the length ofthe neutral axis, L₀ is Θ×R, where Θ is in radians and R is the bendradius, the length of the outer fiber, L₁ is Θ×(R+t/2), where Θ is inradians and R is the bend radius and t is the thickness, ε_(x) on theouter fiber is (L₁−L₀)/L₀, and thus,ε_(x)=[Θ×(R+t/2)−(Θ×R)]×1/(Θ×R)=t/2R. The equation σ_(x)=[E/(1−ν²)]·t/2Rbecomes the thin plate bending equation above (σ_(x)=Et/2R(1−ν²)).

In one or more embodiments, the sintered article or the portion of thesintered article, when flattened at least to magnitudes described above,exhibits a maximum in plane stress (which is defined as the maximumabsolute value of stress regardless of whether it is compressive stressor tensile stress, as determined by the thin plate bend bendingequation) of less than or equal to 25% of the bend strength (which ismeasured by 2-point bend strength) of the sintered article. For example,the maximum in plane stress of the sintered article or the portion ofthe sintered article may be less than or equal to 24%, less than orequal to 22%, less than or equal to 20%, less than or equal to 18%, lessthan or equal to 16%, less than or equal to 15%, less than or equal to14%, less than or equal to 12%, less than or equal to 10%, less than orequal to 5%, or less than or equal to 4%, of the bend strength of thesintered article.

In one or more embodiments, the sintered article or a portion of thesintered article is flattenable such that the sintered article orportion of the sintered article exhibits a maximum in plane stress ofless than or equal to 1% of the Young's modulus of the sintered article,when flattened as described herein. In one or more embodiments, themaximum in plane stress of the sintered article may be less than orequal to 0.9%, 0.8%, 0.7%, 0.6%, 0.5%, 0.4%, 0.3%, 0.2%, 0.1% or 0.05%of the Young's modulus of the sintered article.

In one or more embodiments, the sintered article or a portion of thesintered article is flattenable such that when the sintered article orthe portion of the sintered article has a thickness in a range fromabout 40 μm to about 80 μm (or other thicknesses disclosed herein) andis bent to a bend radius of greater than 0.03 m, the sintered article orportion hereof exhibits a maximum in plane stress of less than or equalto 25% of the bend strength of the article. In one or more embodiments,the sintered article or a portion of the sintered article is flattenablesuch that when the sintered article or the portion of the sinteredarticle has a thickness in a range from about 20 μm to about 40 μm (orother thicknesses disclosed herein) and is bent to a bend radius ofgreater than 0.015 m, the sintered article or a portion of the sinteredarticle exhibits a maximum in plane stress of less than or equal to 25%of the bend strength (as measured by 2-point bend strength) of thearticle. In one or more embodiments, when the sintered article has athickness in a range from about 3 μm to about 20 μm (or otherthicknesses disclosed herein) and is bent to a bend radius of greaterthan 0.0075 m, the sintered article or a portion of the sintered articleexhibits a maximum in plane stress of less than or equal to 25% of thebend strength (as measured by 2-point bend strength) of the article.

In one or more embodiments, the sintered article or a portion of thesintered article is flattenable such that when the sintered article orthe portion of the sintered article has a thickness of about 80 μm (orother thicknesses disclosed herein) and is bent to a bend radius ofgreater than 0.03 m, the sintered article or portion hereof exhibits amaximum in plane stress of less than or equal to 25% of the bendstrength of the article. In one or more embodiments, the sinteredarticle or a portion of the sintered article is flattenable such thatwhen the sintered article or the portion of the sintered article has athickness of about 40 μm (or other thicknesses disclosed herein) and isbent to a bend radius of greater than 0.015 m, the sintered article or aportion of the sintered article exhibits a maximum in plane stress ofless than or equal to 25% of the bend strength (as measured by 2-pointbend strength) of the article. In one or more embodiments, when thesintered article has a thickness of about 20 μm (or other thicknessesdisclosed herein) and is bent to a bend radius of greater than 0.0075 m,the sintered article or a portion of the sintered article exhibits amaximum in plane stress of less than or equal to 25% of the bendstrength (as measured by 2-point bend strength) of the article.

In one or more embodiments, the sintered article or a portion thereof isflattenable such that the sintered article or a portion thereof exhibitsa maximum in plane stress of less than 250 MPa when flattened to withina distance of 0.05 mm, 0.010 mm or 0.001 mm from the flattening planeusing either flattening method (i.e., pinching between two rigidparallel surfaces or against a rigid surface). In one or moreembodiments, the maximum in plane stress may be about 225 MPa or less,200 MPa or less, 175 MPa or less, 150 MPa or less, 125 MPa or less, 100MPa or less, 75 MPa or less, 50 MPa or less, 25 MPa or less, 15 MPa, 14MPa or less, 13 MPa or less, 12 MPa or less, 11 MPa or less, 10 MPa orless, 9 MPa or less, 8 MPa or less, 7 MPa or less, 6 MPa or less, 5 MPaor less, or 4 MPa or less.

In one or embodiments, the sintered article or a portion thereof isflattenable such that a force of less than 8 N (or 7 N or less, 6 N orless, 5 N or less, 4 N or less, 3 N or less, 2 N or less, 1 N or less,0.5 N or less, 0.25 N or less, 0.1 N or less, or 0.05 N or less) isrequired to flatten the sintered article or a portion thereof within adistance of 0.05 mm, 0.010 mm or 0.001 mm from the flattening bypinching between two rigid parallel surfaces.

In one or more embodiments, the sintered article or a portion thereof isflattenable such that a pressure of 0.1 MPa or less is required to pushthe sintered article (or portion of the sintered article) flat to withina distance of 0.05 mm, 0.010 mm or 0.001 mm from the flattening plane,when the sintered article (or portion of the sintered article) is pushedagainst a rigid surface. In some embodiments, the pressure may be about0.08 MPa or less, about 0.06 MPa or less, about 0.05 MPa or less, about0.04 MPa or less, about 0.02 MPa or less, about 0.01 MPa or less, about0.008 MPa or less, about 0.006 MPa or less, about 0.005 MPa or less,about 0.004 MPa or less, about 0.002 MPa or less, about 0.001 MPa orless, or 0.0005 MPa or less.

According to another aspect, the sintered article may be a sintered tapematerial that is rolled into a rolled sintered article as shown in FIG.34A. In such embodiments, the rolled sintered article includes a core1100 and a sintered article 1200 (according to one or more embodimentsdescribed herein) wound around the core. In one or more embodiments, thecore is cylindrical and has a diameter 1240 of less than 60 cm (or about20 inches). For example, the core may have a diameter of about 55 cm orless, 50 cm or less, about 48 cm or less, about 46 cm or less, about 45cm or less, about 44 cm or less, about 42 cm or less, about 40 cm orless, about 38 cm or less, about 36 cm or less, about 35 cm or less,about 34 cm or less, about 32 cm or less, about 30 cm or less, about 28cm or less, about 26 cm or less, about 25 cm or less, about 24 cm orless, about 22 cm or less, about 20 cm or less, about 18 cm or less,about 16 cm or less, about 15 cm or less, about 14 cm or less, about 12cm or less, about 10 cm or less, about 8 cm or less, about 6 cm or less,about 5 cm or less, about 4 cm or less, or about 2 cm or less. In otherembodiments the core is otherwise shape and the roll bends around thecore in arcs corresponding to the above diameter dimensions.

In one or more embodiments, the sintered article wound around the coreis continuous and has the dimensions otherwise described herein (e.g., awidth that is about 5 mm or greater, a thickness in a range from about 3μm to about 1 mm, and a length is about 30 cm or greater).

Spooling of a continuous sintered article (and in particular, acontinuous sintered inorganic material such as ceramics) onto a corepresents several challenges because the sintered article has cross webshape, and web tensions that the sintered article can tolerate,particularly in the binder burn out and bisque states, are extremely low(e.g., tensions of gram level magnitude). Furthermore, the modulus ofthe sintered material can be very high (e.g., up to and including about210 GPa) and therefore, the sintered article does not stretch undertension and, when wound around a core, the resulting wound rollintegrity may be poor. During handling the successive convolutions, acontinuous sintered article can easily telescope (i.e., the successivewraps can move out of alignment).

Applicants have found that rolled sintered article of one or moreembodiments has superior integrity by using a compliant interlayersupport material when spooling the continuous sintered article onto acore. In one or more embodiments, the continuous sintered article isdisposed on an interlayer support material and the continuous sinteredarticle and interlayer support material are wound around the core suchthat each successive wrap of the continuous sintered article isseparated from one another by the interlayer support material. Asdescribed above with reference to FIG. 3, the sintered article (orsintered tape material) 40 is wound upon uptake reel 44. The interlayersupport material 46 is or may be paid off of a reel 48 and theinterlayer support material 46 is or may be wound onto uptake reel 44such that a layer of interlayer support material 46 is located betweeneach layer, most, or at least some layers of continuous sintered article1000 (e.g., sintered article 1200 or sintered tape material 40) onuptake reel 44. This arrangement forms the rolled sintered material 50.

Referring to FIG. 34B, a detailed cross-sectional view of the rolledsintered article 1200 of FIG. 34A is shown according to an exemplaryembodiment, where the sintered article 1200 has been twice rolled aroundthe core 1100 and interlayer support material 46 is positioned betweenthe sintered article 1200 and the core 1100, and then between successivewinds of the sintered article 1200. As may be intuitive from FIG. 34B,when viewed from an end, the sintered article 1200 (in this case a tape)and the interlayer support material 46 form intertwined spirals aboutthe core 1100. In other contemplated embodiments, the sintered articlemay be cut into discrete sheets and still wound on a core and separatedfrom adjoining winds by a continuous interlayer support material 46,such as where the net length of the sheets when added together is alength L as described herein. As shown in FIG. 34B, in variousembodiments, the rolled sintered article includes interlayer supportmaterial 46 between each layer of rolled sintered article (e.g.,sintered article 1000, sintered article 1200 or sintered tape material40) is shown according to an exemplary embodiment. In variousembodiments, the interlayer support material includes a first majorsurface and a second major surface opposing the first major surface, aninterlayer thickness (t) defined as a distance between the first majorsurface and the second major surface, an interlayer width defined as afirst dimension of one of the first or second surfaces orthogonal to theinterlayer thickness, and an interlayer length defined as a seconddimension of one of the first or second major surfaces orthogonal toboth the interlayer thickness and the interlayer width of the interlayersupport material. In one or more exemplary embodiments, the interlayerthickness is greater than the thickness of the sintered article. In oneor more embodiments the interlayer width may be greater than the widthof the rolled sintered article.

In one or more embodiments, the interlayer support material 46 comprisesa tension (or is under a tension) that is greater than a tension on thecontinuous sintered article, as measured by a load cell. In one or moreembodiments, the interlayer support material has a relatively lowmodulus (compared to the sintered article) and thus is stretched underlow tension. It is believed that this creates higher interlayer rollpressures that improve the wound roll integrity. Furthermore, thetension in the wound roll in some embodiments is controlled bycontrolling the tension applied to the interlayer support material andthat tension can be tapered as a function of wound roll diameter. Insome such embodiments, the interlayer support material 46 is in tension,while the sintered article (e.g., tape) is in compression.

In one or more embodiments, the interlayer support material is thicknesscompliant (i.e., the thickness can be decreased by applying pressure toa major surface and can therefore compensate for variation in the crossweb shape or thickness in the sintered article generated by thesintering process). In some such embodiments, when viewed from the side,the sintered article may be hidden within the roll by the interlayersupport material, where the interlayer support material contactsadjoining winds of interlayer support material and, at least to somedegree, shields and isolates the sintered article, such as where theinterlayer support material is wider than the sintered article as shownin FIG. 34B and extends beyond both width-wise edges of the sinteredarticle (e.g. tape).

Referring to FIG. 34A, in one or more embodiments, the rolled article ison a cylindrical core and has a diameter 1220 and a side wall width 1230that are substantially constant. The interlayer support material enablesspooling of the continuous or non-continuous sintered article around thecore, without causing telescoping, which can increase the side wallwidth of the rolled article. In some embodiments, the core comprises acircumference and a core centerline along the circumference, thecontinuous sintered article comprises an article centerline along adirection of the length, and the distance between the core centerlineand the article centerline is 2.5 mm or less, along at least 90% or theentire length of the continuous or non-continuous sintered article.

In one or more embodiments, the rolled article comprises a frictionalforce between the interlayer support material and the continuous ornon-continuous sintered article that is sufficient to resist lateraltelescoping of the successive convolutions in the wound roll, even whenvery low tension is applied to the interlayer support material. Aconstant tension may be applied to the interlayer support material;however, the tension applied to the interior portions of the rolledarticle toward the core may be greater than the tension applied toexterior portions of the rolled article away from the core due to thediameter of the rolled article increasing from the core to the exteriorportions as more interlayer support material and continuous sinteredarticle is wound around the core. This compresses or may compress therolled article, which, when coupled with the friction between theinterlayer support material and the continuous sintered article,prevents or limits telescoping and relative movement between sinteredarticle surfaces to at least help prevent defects.

In one or more embodiments, the interlayer support material comprisesany one of or both a polymer and a paper. In some embodiments, theinterlayer support material is a combination of polymer and paper. Inone or more embodiments, the interlayer support material may include afoamed polymer. In some embodiments, the foamed polymer is closed cell.

According to another aspect, the sintered articles described herein maybe provided as a plurality of discrete sintered articles, as disclosedabove, as illustrated in FIG. 35 and FIG. 36. In one or moreembodiments, the discrete sintered articles may be formed from a rolledsintered article or a continuous sintered article, as described herein.For example, the discrete sintered articles may be laser cut orotherwise separated from a larger sintered article (which may be insheet or tape form). In one or more embodiments, each of the pluralityof discrete sintered articles has a uniformity or consistency withrespect to some or all others of the plurality of discrete sinteredarticles, as may be due to the improved processes and materialproperties described herein. In one or more embodiments, each of theplurality of sintered articles include a first major surface, a secondmajor surface opposing the first major surface, and a body extendingbetween the first and second surfaces. The body includes a sinteredinorganic material and a thickness (t) defined as a distance between thefirst major surface and the second major surface, a width defined as afirst dimension of one of the first or second surfaces orthogonal to thethickness, and a length defined as a second dimension of one of thefirst or second surfaces orthogonal to both the thickness and the width.As may be intuitive, the discrete sheets or other sintered articles cutor formed from a longer tape have uniform and consistent compositions asdisclosed above, uniform and consistent crystal structure, uniform andconsistent thickness, levels of defects, and other properties describedherein that are or may be present in a tape or other elongate articlemanufactured with the inventive equipment and processes disclosedherein.

In one or more embodiments, some, most, or each of the plurality ofsintered articles is flattenable, as described herein. In one or moreembodiments, some, most, or each of the plurality of sintered articles,when flattened, exhibits a maximum in plane stress (which is defined asthe maximum absolute value of stress regardless of whether it iscompressive stress or tensile stress, as determined by the thin platebend bending equation) of less than or equal to 25% of the bend strength(which is measured by 2-point bend methods) of the sintered article. Forexample, the maximum in plane stress of some, most, or each of theplurality of sintered articles may be less than or equal to 24%, lessthan or equal to 22%, less than or equal to 20%, less than or equal to18%, less than or equal to 16%, less than or equal to 15%, less than orequal to 14%, less than or equal to 12%, less than or equal to 10%, lessthan or equal to 5%, or less than or equal to 4%, of the bend strengthof the sintered article.

In one or more embodiments, some, most, or each of the plurality ofsintered articles is flattenable such that some, most, or each of theplurality of sintered articles exhibits a maximum in plane stress ofless than or equal to 1% of the Young's modulus of the sintered article,when flattened as described herein. In one or more embodiments, themaximum in plane stress of some, most, or each of the plurality ofsintered articles may be less than or equal to 0.9%, 0.8%, 0.7%, 0.6%,0.5%, 0.4%, 0.3%, 0.2%, 0.1% or 0.05% of the Young's modulus of therespective sintered article.

In one or more embodiments, some, most, or each of the plurality ofsintered articles is flattenable such that when the sintered article hasa thickness in a range from about 40 μm about 80 μm (or other thicknessdisclosed herein) and is bent to a bend radius of greater than 0.03 m,the sintered article exhibits a maximum in plane stress of less than orequal to 25% of the bend strength of the article. In one or moreembodiments, some, most, or each of the plurality of sintered articlesis flattenable such that when the sintered article has a thickness in arange from about 20 μm to about 40 μm (or other thickness disclosedherein) and is bent to a bend radius of greater than 0.015 m, thesintered article exhibits a maximum in plane stress of less than orequal to 25% of the bend strength (as measured by 2-point bend strength)of the article. In one or more embodiments, some, most, or each of theplurality of sintered articles is flattenable such that when thesintered article has a thickness in a range from about 3 μm to about 20μm (or other thickness disclosed herein) and is bent to a bend radius ofgreater than 0.0075 m, the sintered article exhibits a maximum in planestress of less than or equal to 25% of the bend strength (as measured by2-point bend strength) of the article.

In one or more embodiments, some, most, or each of the plurality ofsintered articles is flattenable such that when the sintered article hasa thickness of about 80 μm (or other thickness disclosed herein) and isbent to a bend radius of greater than 0.03 m, the sintered articleexhibits a maximum in plane stress of less than or equal to 25% of thebend strength of the article. In one or more embodiments, some, most, oreach of the plurality of sintered articles is flattenable such that whenthe sintered article has a thickness of about 40 μm (or other thicknessdisclosed herein) and is bent to a bend radius of greater than 0.015 m,the sintered article exhibits a maximum in plane stress of less than orequal to 25% of the bend strength (as measured by 2-point bend strength)of the article. In one or more embodiments, some, most, or each of theplurality of sintered articles is flattenable such that when thesintered article has a thickness of about 20 μm (or other thicknessdisclosed herein) and is bent to a bend radius of greater than 0.0075 m,the sintered article exhibits a maximum in plane stress of less than orequal to 25% of the bend strength (as measured by 2-point bend strength)of the article.

In one or more embodiments, some, most, or each of the plurality ofsintered articles is flattenable such that the sintered article exhibitsa maximum in plane stress of less than 250 MPa when flattened to withina distance of 0.05 mm, 0.01 mm, or 0.001 mm from the flattening planeusing either flattening method (i.e., pinching between two rigidparallel surfaces or against a rigid surface). In one or moreembodiments, the maximum in plane stress may be about 225 MPa or less,200 MPa or less, 175 MPa or less, 150 MPa or less, 125 MPa or less, 100MPa or less, 75 MPa or less, 50 MPa or less, 25 MPa or less, 15 MPa, 14MPa or less, 13 MPa or less, 12 MPa or less, 11 MPa or less, 10 MPa orless, 9 MPa or less, 8 MPa or less, 7 MPa or less, 6 MPa or less, 5 MPaor less, or 4 MPa or less.

In one or embodiments, some, most, or each of the plurality of sinteredarticles is flattenable such that a force of less than 8 N (or 7 N orless, 6 N or less, 5 N or less, 4 N or less, 3 N or less, 2 N or less, 1N or less, 0.5 N or less, 0.25 N or less, 0.1 N or less, or 0.05 N orless) is required to flatten the sintered article or a portion thereof,respectively, when the sintered article is flattened to within adistance of 0.05 mm, 0.01 mm, or 0.001 mm from the flattening bypinching between two rigid parallel surfaces.

In one or embodiments, some, most, or each of the plurality of sinteredarticles is flattenable such that a pressure of 0.1 MPa or less isrequired to push the sintered article flat to within a distance of 0.05mm, 0.01 mm, or 0.001 mm from the flattening plane, when pushed againsta rigid surface. In some embodiments, the pressure may be about 0.08 MPaor less, about 0.06 MPa or less, about 0.05 MPa or less, about 0.04 MPaor less, about 0.02 MPa or less, about 0.01 MPa or less, about 0.008 MPaor less, about 0.006 MPa or less, about 0.005 MPa or less, about 0.004MPa or less, about 0.002 MPa or less, about 0.001 MPa or less, or 0.0005MPa or less.

In one or more embodiments, the thickness of some, most, or each of theplurality of sintered articles is within a range from about 0.7t toabout 1.3t (e.g., from about 0.8t to about 1.3t, from about 0.9t toabout 1.3t, from about t to about 1.3t, from about 1.1t to about 1.3t,from about 0.7t to about 1.2t, from about 0.7t to about 1.1t, from about0.7t to about 1t, or from about 0.9t to about 1.1t), where t is thethickness values disclosed herein.

In one or more embodiments, some, most, or each of the plurality ofsintered article exhibits compositional uniformity. In one or moreembodiments, at least 50% (e.g., about 55% or more, about 60% or more,or about 75% or more) of the plurality of sintered articles comprise anarea and a composition, wherein at least one constituent of thecomposition (as described herein) varies by less than about 3 weight %across the area. In some embodiments, at least one constituent of thecomposition varies by about 2.5 weight % or less, about 2 weight % orless, about 1.5 weight % or less, about 1 weight % or less, or about 0.5weight % or less), across that area. In one or more embodiments, thearea is about 1 square centimeter of the sintered article, or the areais the entire surface area of the sintered articles.

In one or more embodiments, some, most, or each of the plurality ofsintered article exhibits crystalline structure uniformity. In one ormore embodiments, at least 50% (e.g., about 55% or more, about 60% ormore, or about 75% or more) of the plurality of sintered articlescomprise an area and a crystalline structure with at least one phasehaving a weight percent that varies by less than about 5 percentagepoints (as described herein) across the area. For illustration only,some, most, or each of the plurality of sintered article may include atleast one phase that constitutes 20 weight % of the sintered articleand, in at least 50% (e.g., about 55% or more, about 60% or more, orabout 75% or more) of the plurality of sintered articles, this phase ispresent in an amount in a range from about 15 weight % to about 25weight % across the area. In one or more embodiments, at least 50%(e.g., about 55% or more, about 60% or more, or about 75% or more) ofsome, most, or each of the plurality of sintered articles comprise anarea and a crystalline structure with at least one phase having a weightpercent that varies by less than about 4.5 percentage points, less thanabout 4 percentage points, less than about 3.5 percentage points, lessthan about 3 percentage points, less than about 2.5 percentage points,less than about 2 percentage points, less than about 1.5 percentagepoints, less than about 1 percentage point, or less than about 0.5percentage points, across that area. In one or more embodiments, thearea is about 1 square centimeter of the sintered article, or the areais the entire surface area of the sintered articles.

In one or more embodiments, at least 50% (e.g., about 55% or more, about60% or more, or about 75% or more) of the plurality of sintered articlecomprise an area and a porosity (as described herein) that varies byless than about 20%. Accordingly, in one example, some, most, or each ofthe plurality of sintered articles has a porosity of 10% by volume andthis porosity is within a range from about greater than 8% by volume toless than about 12% by volume across the area in at least 50% of theplurality of sintered articles. In one or more specific embodiments, atleast 50% of the plurality of sintered articles comprises an area andhas a porosity that varies by 18% or less, 16% or less, 15% or less, 14%or less, 12% or less, 10% or less, 8% or less, 6% or less, 5% or less,4% or less or about 2% or less across the area. In one or moreembodiments, the area is about 1 square centimeter of the sinteredarticle, or the area is the entire surface area of the sintered article.

Examples 5-6 and Comparative Examples 7-8

Examples 5-6 and Comparative Examples 7-8 are discrete sintered articlesformed from a continuous sintered article of tetragonal or tetrazirconia polycrystalline material. Examples 5-6 were formed according tothe process and system described herein and Comparative Examples 7-8were formed using other processes and systems that do not include atleast some of the presently disclosed technology (e.g., tension control,zoned sintering furnace, air flow control). Each of Examples 5-6 andComparative Examples 7-8 had length of 55.88 mm, a width of 25.4 mm, athickness of 0.04 mm, and a corner radius of 2 mm. Each of Examples 5-6and Comparative Examples 7-8 had a Young's modulus of 210 GPa, Poisson'sratio (ν) of 0.32, and a density (ρ) of 6 g/cm³.

Example 5 had a c-shape as shown in FIG. 35, with 0.350 mm shapemagnitude. Example 6 had a saddle shape as shown in FIG. 36, with 0.350mm shape magnitude. Comparative Example 7 had a gullwing shape with0.350 mm shape magnitude as shown in FIG. 37. Comparative Example 8 hada gullwing shape with 0.750 mm shape magnitude as shown in FIG. 38. Theshape magnitude of each sintered article about the plane prior toflattening is compared in FIG. 39.

The flattenability of the Examples was evaluated using the two loadingmethods otherwise described herein (i.e., pinching the sintered articlesbetween two rigid parallel surfaces or applying a surface pressure onone major surface of the sintered article to push the sintered articleagainst a rigid surface, to flatten the sintered article along aflattening plane).

FIG. 40 shows the force (in N) required to pinch each of the sinteredarticles of Examples 5-6 and Comparative Examples 7-8 flat to within adistance of 0.001 mm from the flattening plane, by pinching between tworigid parallel surfaces. As shown in FIG. 40, Examples 5-6 requiresignificantly less force to flatten the sintered articles, indicating agreater flattenability. Moreover, the ability to flatten the sinteredarticles at such low force indicates that such articles can bemanipulated in or subjected to downstream processing without fracturing,breaking or otherwise forming defects. Downstream processes may include,for example, the application of coatings which may include conductive ornonconductive coatings. This same flattenability is also demonstratedwhen the pressure required to push each of the sintered articles ofExamples 5-6 and Comparative Examples 7-8 flat to within a distance of0.001 mm from the flattening plane, by pushing the sintered articleagainst a rigid surface, was measured. The results are shown in FIG. 41,which demonstrate Examples 5-6 require a significantly less pressure toflatten when compared to Comparative Examples 7-8. FIG. 42 shows themaximum in plane surface stress in the flattened sintered articles ofExamples 5-6 and Comparative Examples 7-8. Examples 5-6 exhibit lessthan 11 MPa of stress, while Comparative Examples 7-8 exhibit more than20 times that stress, indicating the sintered articles of ComparativeExamples 7-8 are more likely to fracture, break or have defects duringdownstream processing. The location of the stress in Example 5 is shownin FIGS. 43A (bottom surface stress when flattened) and 43B (top surfacestress when flattened). The location of the stress in Example 6 is shownin FIGS. 44A (bottom surface stress when flattened) and 44B (top surfacestress when flattened). The location of the stress in ComparativeExample 7 is shown in FIGS. 45A (bottom surface stress when flattened)and 45B (top surface stress when flattened). In Comparative Example 7,on the bottom surface, the central portion exhibits a tensile stress of208.6 MPa, which is flanked on both sides by compressive stress of−254.6 MPa. Correspondingly, on the front surface, the central portionis under a compressive stress of about −208.6 MPa and is flanked on bothsides by a tensile stress of 254.6 MPa. The location of the stress inComparative Example 8 is shown in FIGS. 46A (bottom surface stress whenflattened) and 46B (top surface stress when flattened). In ComparativeExample 8, on the bottom surface, the central portion exhibits a tensilestress of 399.01 MPa, which is flanked on both sides by compressivestress of −473.63 MPa. Correspondingly, on the front surface, thecentral portion is under a compressive stress of about −399.08 MPa andis flanked on both sides by a tensile stress of 473.60 MPa. The highstress at the points X in Comparative Examples 7-8 indicate thesesintered articles will likely fracture along the high stress locations.

In some semiconductor packages and similar light emitting diode (LED)containing packages, much of the electrical energy provided to orthrough the package may be lost or dissipated as heat energy. The heatdissipation capacity of these and similar semiconductor packages may bea limiting factor when trying to provide additional electrical energy(or current) through the package. Also, in at least some LED containingpackages, brightness of the LED may be limited by the heat dissipationcapacity of the LED containing package. It may be desirable to reduceand maintain the temperature of the components in a semiconductorpackage, such as from about 75° C. to about 85° C.

In one or more embodiments and referring to FIG. 47, sintered article asdescribed herein (e.g., sintered article 1000, sintered article 1200, orsintered tape material 40) is directly or indirectly joined, bonded,connected, or otherwise attached to a substrate 1500 to form a package2000. Sintered article 1000 may act as a dielectric in package 2000. Insome embodiments, package 2000 is a semiconductor package, an electricalpackage, a power transmission package, a light emitting diode (LED)package, or similar. Package 2000 of the present disclosure providesimproved performance (e.g., heat dissipation capacity, lower thermalresistance, etc.) when compared with conventional packages. In othersuch embodiments, sintered article as described herein (e.g., sinteredarticle 1000, sintered article 1200, or sintered tape material 40) is oris also substrate 1500.

In some embodiments, package 2000 includes an interlayer 1300 betweensubstrate 1500 and sintered article 1000. Interlayer 1300 may include amaterial that joins, bonds, connects, or otherwise attaches orfacilitates attachment of substrate 1500 and sintered article 1000.Interlayer 1300 may include a plurality of discrete layers joined orjoined together to form interlayer 1300. In some embodiments, interlayer1300 is a material with high thermal conductivity properties such thatheat generated by electrical components (e.g., a semiconductor device orchip) or metal-based layers is conducted through interlayer 1300 tosubstrate 1500. In some embodiments, interlayer 1300 includes a thermalconductivity greater than that of sintered article 1000. In someembodiments, interlayer 1300 includes a thermal conductivity less thansubstrate 1500. Interlayer 1300 may have a thermal conductivity greaterthan about 8 W/m·K to about 20 W/m·K, greater than about 8 W/m·K toabout 16 W/m·K, or greater than about 8 W/m·K to about 13 W/m·K, orgreater than about 9 W/m·K to about 12 W/m·K, such as 8, 9, 10, 11, 12,13, 14, 15, 16, 17, 18, 19, or 20 W/m·K, including all ranges andsubranges therebetween. In some embodiments, interlayer 1300 is anadhesive-like material. In some embodiments, interlayer 1300 is acompliant material which is configured to deform and/or to withstandshearing forces from coefficient of thermal expansion (CTE) differencesbetween substrate 1500 and sintered article 1000 which occur as a resultof heating and cooling of package 2000.

In some embodiments, interlayer 1300 includes a matrix of a polyimide,an epoxy, or combinations thereof. In some embodiments, the matrix ofinterlayer 130 may include nonconductive particles (e.g., boronnitride), conductive particles (e.g., silver, copper, etc.), orcombinations thereof. The conductive and/or non-conductive particles maybe homogeneously or non-homogeneously distributed throughout the matrixof interlayer 130. In some embodiments, interlayer 1300 conducts heatfrom metal-based layer 1350 and components 1401 (FIG. 50(e)) andtransfers the conducted heat to substrate 1500. In some embodiments,interlayer 1300 may have a length (L) and a width (W) substantiallysimilar to that of one or both of substrate 1500 and/or sintered article1000. In some embodiments, interlayer may have a thickness (t₂) fromabout 0.1 μm to about 100 μm, or from about 10 μm to about 75 μm, orfrom about 15 μm to about 35 μm, or even from about 20 μm to about 40μm, such as 5, 10, 15, 20, 25, 30, 35, or 40 μm, including all rangesand subranges therebetween.

In one or more embodiments, substrate 1500 includes a first majorsurface 1510, a second major surface 1520 opposing the first majorsurface, and a body 1530 extending between the first and second surfaces1510, 1520. Sintered article 1000 may be directly or indirectly joined,bonded, connected, or otherwise attached to first major surface 1510 orsecond major surface 1520 of substrate 1500. The body 1530 has athickness (t₁) defined as a distance between the first major surface1510 and the second major surface 1520, a width (W₁) defined as a firstdimension of one of the first or second surfaces orthogonal to thethickness, and a length defined as a second dimension of one of thefirst or second surfaces orthogonal to both the thickness and the width.In one or more embodiments, substrate 1500 includes opposing minorsurfaces 1540 that define the width W₁. In some embodiments, the lengthsand widths of sintered article 1000 and substrate 1500, respectively,are substantially equivalent (e.g., the lateral dimensions within 5% ofeach other). In some embodiments, the thickness (t₁) of substrate 1500is greater than the thickness (t) of sintered article 1000, such as thethicknesses (t) disclosed herein for sintered article 1000. In someembodiments, the thickness (t₁) of substrate 1500 is about 25% greaterthan, about 50% greater than, about 75% greater than, about 100% greaterthan, about 200% greater than, about 500% greater than or more than thethickness (t) of sintered article 1000. In some embodiments, thethickness (t₁) of substrate 1500 is from about 0.5 mm to about 5.0 mm,or from about 1.0 mm to about 2.0 mm, or from about 1.0 mm to about 1.6mm, or even from about 1.2 mm to about 1.5 mm. In some embodiments,substrate 1500 acts as a heat sink for package 2000. In someembodiments, substrate 1500 comprises an electrically conductive metal,such as aluminum, copper, or combinations thereof.

FIGS. 47 and 48 provide cross-sectional views of a segment of an examplepackage 2000 in which interlayer 1300 joins substrate 1500 to sinteredarticle 1000. A metal-based layer 1350 may be provided on a majorsurface of sintered article 1000 opposite the major surface bonded tointerlayer 1300. That is, sintered article 1000 may include interlayer1300 on one major surface and metal-based layer 1350 on the oppositemajor surface. Interlayer 1300 may be applied to one or both ofsubstrate 1500 and sintered article 1000. Subsequently, substrate 1500and sintered article 1000 may be assembled or joined together withinterlayer 1300 between a major surface of each. Interlayer 1300 may beactivated with thermally energy, actinic wavelengths, pressure, or othersimilar method to join, bond, connect, or otherwise attach substrate1500 to sintered article 1000 via interlayer 1300.

As illustrated in FIG. 47, one or both of major surfaces 1510, 1520 ofsubstrate 1500 may be patterned to include grooves 1325. Grooves 1325may assist with joining interlayer 1300 to substrate 1500. Grooves 1325may also help minimize sheer stresses experienced by interlayer 1300 asa result of CTE differences between substrate 1500 and sintered article1000. In some embodiments, grooves 1325 cover at least a portion of amajor surface of substrate 1500. Grooves 1325 may have a depth fromabout 0.1 μm to about 1 mm, or from about 10 μm to about 50 μm in amajor surface of substrate 1500. Interlayer 1300 may extend at leastpartially within grooves 1325 of substrate 1500. Grooves 1325 may berectangular, square, circular, triangular, or other similar shapes orcombinations of several shapes in cross-section and may be continuous,dashed, or otherwise extending on a major surface of sintered article1000.

Metal-based layer 1350 may be directly or indirectly joined to sinteredarticle 1000 by electroplating, printing, physical vapor deposition,chemical vapor deposition, sputtering, or other similar techniques.Metal-based layer 1350 is an electrically conductive material capable ofconducting or providing electrical energy (or current) across andthrough package 2000. In some embodiments, metal-based layer isconfigured to minimize electrical resistance and heat generation acrossits length. In some embodiments, metal-based layer 1350 comprisescopper, nickel, gold, silver, gold, brass, lead, tin, and combinationsthereof. Metal-based layer 1350 may be indirectly joined to sinteredarticle 1000 via a seed layer 1375. That is, seed layer 1375 may providea foundation for joining metal-based layer 1350 to sintered article1000. In some embodiments, seed layer 1375 that joins metal-based layer1350 to sintered article 1000 is “reflowed” in a reflow oven toelectrically connect the metal-based layer 1350 to other electricalcomponents in the package 2000. In some embodiments, seed layer 1375comprises tin, titanium, tungsten, lead, or combinations thereof. Seedlayer 1375 may be applied to a major surface of sintered article 1000 byelectroplating, printing, physical vapor deposition, chemical vapordeposition, sputtering, or other similar techniques.

In some embodiments, metal-based layer 1350 may be directly orindirectly joined to sintered article 1000 before, during, or aftersintered article 1000 is joined to substrate 1500. In some embodiments,metal-based layer 1350 is a continuous, semi-continuous, ordiscontinuous array or “circuit” on a major surface of sintered article1000. In some embodiments, prior to applying metal-based layer 1350and/or seed layer 1375 on sintered article 1000, portions of one or bothmajor surfaces of sintered article 1000 may be masked or covered toprevent application of metal-based layer 1350 and/or seed layer 1375 onsaid masked portions of sintered article 1000. That is, the maskingportions of one or both major surfaces of sintered article 1000 may beused to form a semi-continuous or discontinuous array or “circuit” ofmetal-based layer 1350 and/or seed layer 1375 on a major surface ofsintered article 1000. After metal-based layer 1350 is applied to anunmasked portion of a major surface of sintered article 1000, maskingmay be removed to expose that portion of the major surface (without ametal based layer and/or seed layer thereon) where the masking waspresent. FIGS. 47 and 49 provide examples of metal-based layer 1350 asan array on a major surface of sintered article. Metal-based layer 1350includes a thickness (t₃) from about 0.1 μm to about 1 mm, or from about2 μm to about 100 μm, from about 5 μm to about 70 μm, or even from about5 μm to about 50 μm.

In one or more embodiments, package 2000 includes a semiconductor deviceor chip 1400. In some embodiments, semiconductor device 1400 is directlyor indirectly joined, bonded, connected, or otherwise attached to firstmajor surface 1010 or second major surface 1020 of substrate 1000.Semiconductor device 1400 may be indirectly joined to sintered article1000 via seed layer 1375 as shown in FIG. 49. Semiconductor device 1400may include one or more light emitting diodes (LED). In someembodiments, semiconductor device 1400 is connected to metal-based layer1350 by one or more leads 1450. Leads 1450 may be rigid or flexiblewires or electrical connectors (e.g., similar to the metal-based layer1350) that electrically connect semiconductor device 1400 andmetal-based layer 1350. FIGS. 47 and 49 illustrate lead 1450 as bridgingthe distance between semiconductor device 1400 and metal-based layer1350. Of course, leads 1450 may run along or contact the surface ofsintered article 1300 in one or more embodiments. Leads 1450 may provideelectrical energy between metal-based layer 1350 and semiconductordevice 1400. In some embodiments, electrical energy running throughmetal-based layer 1350 is transmitted through leads 1450 tosemiconductor device 1400. In some embodiments, electrical energyprovided to semiconductor device 1400 powers an LED thereon whichemanates one or more light wavelengths (λ). Semiconductor device 1400may include one or more lenses 1405 to intensify or directly light fromLEDs thereon. Semiconductor device 1400 may also include a phosphormaterial 1475 to filter and transmit specific wavelengths (k)therethrough from light wavelengths (λ) emanating from the LEDs.

In one or more embodiments, methods of making package 2000 includeproviding sintered article 1000. Sintered article 1000 maybe in on aroll including a round or cylindrical core having a diameter of lessthan 60 cm, the continuous sintered article wound around the core.Sintered article 1000 may also be provided as discrete flattenedlengths. In one or more embodiments, methods of making package 2000include providing a carrier or temporary substrate 1499 (FIG. 50), whichmay be on a roll or as a large, flat sheet. In some embodiments, alength of sintered article 1000 is joined, bonded, connected, orotherwise attached to a length of carrier or temporary substrate 1499 toform precursor package 1999. Carrier or temporary substrate 1499 maysupport the sintered article 1000 for subsequently rolling onto a core.In some embodiments, carrier or temporary substrate 1499 supportssintered article 1000 during subsequent processes which may damage,degrade, or destroy substrate 1500. In some embodiments, carrier ortemporary substrate 1499 comprises glass, a polymer, or combinationsthereof. In some embodiments, carrier or temporary substrate 1499 ispolymeric, such as a polyamide tape.

In some embodiments, precursor package 1999 includes a precursorinterlayer 1299 (FIG. 50) between sintered article 1000 and temporarysubstrate 1499. Precursor interlayer 1299 may include a material thatjoins, bonds, connects, or otherwise attaches temporary substrate 1499and sintered article 1000. In some embodiments, precursor interlayer1299 is a high-temperature resistant adhesive. Precursor interlayer 1299may be activated with thermal energy, actinic wavelengths, pressure, orother similar method to join, bond, connect, or otherwise attachtemporary substrate 1499 to sintered article 1000. In some embodiments,precursor interlayer 1299 may be deactivated by similar or differentmeans than that for activation so that sintered article 1000 can bedetached or disconnected from temporary substrate 1499. In someembodiments, precursor interlayer 1299 and temporary substrate 1499 areconfigured to withstand (not degrade) during subsequent processing ofprecursor package 1999, including application of metal-based layer 1350,seed layer 1375, semiconductor device 1400, leads 1450, and/or othersimilar components.

FIG. 50 illustrates a method of forming package 2000 from a precursorpackage 1999. Step (a) in the FIG. 50 illustrates precursor package 1999following applying metal-based layer 1350 on a major surface of sinteredarticle 1000 opposite the surface joined with precursor interlayer 1299.Step (a) in FIG. 50 also illustrates precursor package 1999, followingremoving masking from sintered article 1000 (e.g., between metal-basedlayers 1350). Before or after step (a), seed layer 1375 may be appliedto sintered article 1000. Step (b) in FIG. 50 illustrates applying parts(i.e., semiconductor device 1400 and leads 1450) of components 1401 tosintered article 1000 to electrically connect semiconductor device 1400and metal-based layer 1350. In some embodiments, carrier or temporarysubstrate 1299 and precursor interlayer 1299 are configured to supportsintered article 1000 and not degrade or deform during steps (a) and (b)illustrated in FIG. 50, which may be completed at high temperatures(e.g., up to or greater than 320° C.). Step (c) in FIG. 50 illustratesseparating sintered article 1000 (including metal-based layer 1350,semiconductor device 1400, and leads 1450 thereon) from temporarysubstrate 1499. In some embodiments, step (c) may be completed bydeactivating precursor interlayer 1299 with thermal energy, actinicwavelengths, pulling, or other similar method. In some embodiments,sintered article 1000 (including metal-based layer 1350, semiconductordevice 1400, and leads 1450 thereon) is pulled from temporary substrate1499 by a machine or by hand. In some embodiments, step (c) occurs in areflow furnace while seed layer 1375 or solder electrically connects theparts of component 1401. Precursor interlayer 1299 may transfer withsintered article 1000, with temporary substrate 1499, or with both (aportion on each). Step (c) in FIG. 50 illustrates an embodiment whereprecursor interlayer 1299 is transferred with temporary substrate 1499.In some embodiments, precursor interlayer 1299 may become interlayer1300 in subsequent processing (e.g., heating) or by bonding orcontacting substrate 1500. Step (d) in FIG. 50 illustrates joiningsintered article 1000 and substrate 1500 with interlayer 1300therebetween. In some embodiments, precursor interlayer 1299 may be thesame as interlayer 1300. Step (e) in FIG. 50 illustrates applyingadditional parts (e.g., lens 1405 and phosphor 1475) of components 1401to sintered article 1000. In some embodiments, parts of components 1401may be applied at lower temperatures (e.g., <150° C.) such thatinterlayer 1300 and substrate 1500 are not degraded or deformed whilecompleting the building of components 1401. Package 2000 as shown instep (e) of FIG. 50 may include one or more of components 1401.

FIG. 51 provides another illustrative method of forming package 2000 viaa precursor package 1999. Step (a) of FIG. 51 illustrates providingflattened sintered article 1000 from a rolled core, as flattened sheets,or otherwise. Step (b) of FIG. 51 illustrates joining the flattenedsintered article 1000 and carrier or temporary substrate 1499 to formprecursor package 1999. Precursor interlayer 1299 or a similar suchlayer may be located between sintered article 1000 and carrier ortemporary substrate 1499. Precursor package 1999 may be rolled onto acore, stored, shipped, or sold for subsequent processing. Step (c) ofFIG. 51 illustrates applying metal-based layer 1350 and the parts (e.g.,semiconductor device 1400, leads 1450, lens 1405, phosphor 1475, etc.)of light-emitting components 1401 to sintered article 1000. Step (c) mayinclude several stages which electrically connect metal-based layer 1350with semiconductor device 1400 and any LEDs thereon on sintered article1000. Step (c) may also include a solder reflow operation in a solderfurnace to electrically connect all the parts of components 1401. Step(d) of FIG. 51 illustrates detaching or separating sintered article 1000(including components 1401) and temporary substrate 1499. Step (d) maybe accomplished by pulling sintered article 1000 (including components1401) from temporary substrate 1499 by a machine or by hand. Step (d)may be catalyzed by heat, exposure to actinic wavelengths, cooling,exposure to solvents, or other similar methods. Of course, precursorinterlayer 1299 (if present) may transfer with sintered article 1000,with temporary substrate 1499, or with both (a portion on each). Step(e) of FIG. 51 illustrates joining sintered article 1000 (includingcomponents 1401) and substrate 1500 to form package 2000. In someembodiments, sintered article 1000 (including components 1401) andsubstrate 1500 may be joined by interlayer 1300 or a similar layertherebetween to form package 2000. Step (f) of FIG. 51 illustratescutting package 2000 at different points along its length L₄ into aplurality of segments 2001. Package 2000 may be cut along its length L₄into segments 2001 with localized cutting pressure, laser energy (e.g.,UV ablation laser), or with similar techniques. In some embodiments,each segment 2001 includes at least one or more components 1401.Segments 2001 of package 2000 may be used in a variety of applicationsincluding as a filament for a light bulb, an electronic device, ahandheld device, a heads-up display, a vehicle instrument panel, orsimilar.

FIGS. 52-54 illustrate cross-sectional views of package 2000 includingsintered article 1000 and a “flip-chip” configuration of semiconductordevice 1400. In these embodiments, a segment of package 2000 may includean aperture 1501 in substrate 1500. Aperture 1501 may be formed bydrilling, cutting, or removing part of substrate 1500. Aperture 1501 mayalso be formed by spacing two parts of substrate 1500 apart on one majorsurface of sintered article 1000. In some embodiments, metal-based layer1350 may be joined, bonded, connected, or otherwise attached to the samemajor surface of sintered article 1000 as substrate 1500.

FIG. 52 illustrates an example cross-sectional views of a segment ofpackage 2000 including sintered article 1000 joined with substrate 1500.In some embodiments, metal-based layer 1350 is provided within aperture1501. That is, metal-based layer 1350 is joined on the same majorsurface of sintered article 1000 as substrate 1500. In some embodiments,seed layer 1375 is applied to and bonded with metal-based layer 1350.Seed layer 1375 may assist with bonding metal-based layer 1350 andsemiconductor device 1400 in a “flip-chip” configuration. In one or moreembodiments, seed layer 1375 comprises tin, titanium, tungsten, lead, oralloys thereof. In some embodiments, seed layer 1375 is electricallyconductive and may eliminate the need for leads to electrically connectmetal-based layer and semiconductor device 1400. In some embodiments, avolume 1485 may be formed between sintered article 1000 andsemiconductor device 1400. Together with metal-based layer 1350 and/orseed layer 1375, volume 1485 may be sealed between sintered article 1000and semiconductor device 1400. In some embodiments, an LED onsemiconductor device 1400 is opposite volume 1485 and within aperture1501. In some embodiments, an LED on semiconductor device 1400 is withinvolume 1485. Phosphor material 1475 may be provided within volume 1485.In the FIGS. 52 and 53, sintered article 100 may be translucent orsubstantially transparent such that light wavelengths (λ) emanating froman LED on semiconductor device 1400 transmits through sintered article1000. In some embodiments, sintered article 1000 may transmit from about35% to about 95%, or from about 45% to about 85%, or from about 55% toabout 75%, such as 35%, 40%, 50%, 60%, 65%, 75%, 85%, 90%, 95%, or moreup to 99%, including all ranges and subranges therebetween, of some,most, or all the visible light wavelengths (λ) emanating from an LED ortransmitted through phosphor material 1475.

The total light transmitted (T) through the sintered article 1000 may bedefined by the follow equation 1:T=Φ _(e) ^(t)/Φ_(e) ^(i)  (1)

where,

Φ_(e) ^(t) is the radiant flux transmitted by that surface; and

Φ_(e) ^(i) is the radiant flux received by that surface.

The measurement of these quantities is described in ASTM standard testmethod D1003-13.

Although similar to FIG. 52, FIG. 53 illustrates interlayer 1300 betweensintered article 1000 and substrate 1500. FIG. 53 further illustrates anembodiment where at least a portion of aperture 1501 (shown in FIG. 52)is plugged with substrate 1500 which may be isolated from or connectedwith adjacent portions of substrate 1500. In other embodiments, at leasta portion of aperture 1501 is plugged with a filler material (e.g.,epoxy, plastic, polymeric material, etc.) to seal chip 1400 andmetal-based layer 1350 within package 2000. In FIG. 53, substrate 1500contacts semiconductor device 1500 to conduct heat from semiconductordevice 1400 generated when electrical energy is provided to package2000. In some embodiments, sintered article 1000 includes a hole 1490through its thickness. As illustrated in FIGS. 53 and 55, hole 1490 insintered article 1000 intersects volume 1485. Hole 1490 may allowphosphor material 1475 within volume 1485 to be cooled by ambientconvection. Hole 1490 may also allow light wavelengths (λ) from an LEDin volume 1485 to emanate from package 2000. As shown in FIG. 54, areflector 1480 may be included within volume 1485 and/or hole 1490 tointensify or reflect light wavelengths (λ) emanating from an LED onsemiconductor device 1400. Reflector 1480 may have a conical, ahemispherical, a tapering, or a curved shape. In some embodiments,reflector 1480 may be coated with a coating to intensify lightwavelengths (λ) emanating from an LED on semiconductor device 1400. FIG.55 shows another possible configuration.

In one or more embodiments, the sintered articles described herein maybe used in microelectronics applications or articles. For example, suchmicroelectronics articles may include a sintered article (according toone or more embodiments described herein) including a first majorsurface, a second major surface opposing the first major surface. In oneor more embodiments, the microelectronics article may include acontinuous (e.g., long tape, as described herein) or discrete (e.g.,sheets cut or singulated from a tape) sintered article. In one or moreembodiments, the microelectronics article includes a continuous ordiscrete sintered article having a width of about 1 mm or greater, about1 cm or greater, about 5 cm or greater, or about 10 cm or greater. Inone or more embodiments, the microelectronics article includes asintered article having a length of about 1 m or greater, 5 m orgreater, or about 10 m or greater. In one or more embodiments, themicroelectronics article includes a continuous or discrete sinteredarticle having a thickness of less than 1 mm, about 0.5 mm or less,about 300 micrometers or less, about 150 micrometers or less, or about100 micrometers or less. In one or more embodiments of a microelectronicarticle includes a sintered article having a crystalline ceramic contentby volume of about 10% or greater, about 25% or greater, 50% or greater,about 75% or greater, or about 90% or greater.

In one or more embodiments, the sintered article includes one or morevias (e.g., holes, apertures, wells, pipes, passages, linkages; see hole1490 of FIG. 53) disposed along a given area of the first major surfaceof the sintered article. In one or more embodiments, the vias partiallyor wholly extend through the thickness of the sintered articles. In oneor more embodiments, the vias may be disposed in a pattern that may berepeating or periodic, such as where the vias are formed along the tapein a continuous roll-to-roll process, where the tape may later besingulated to form individual components, such as for semiconductors orother electronics. In one or more embodiments, the vias may be spacedfrom one another such that there is a distance of about 0.5 m or less,10 cm or less, or 5 cm or less between the vias (i.e. at least betweensome, most, or each via and the next closest via). In some embodiments,this via spacing may be present in sintered articles having a thicknessof less than 1 mm, about 0.5 mm or less, about 300 micrometers or less,about 150 micrometers or less, or about 100 micrometers or less. In oneor more specific embodiments, this via spacing may be present insintered articles having a thickness of about 50 micrometers or less.Vias may be cut by laser, masks and etchants, punch, or other methods,such as prior to, during (e.g., when partially sintered) or aftersintering. Forming vias after sintering may help precision of placementand sizing of the vias; however due to the consistency of processes andmaterials described herein, vias may be formed in green tape orpartially sintered tape for example, and accuracy of placement, sizing,wall geometry, etc. may be within desired tolerances for someapplications.

In one or more embodiments, the sintered article includes a conductivelayer (e.g., copper, aluminum, or other conductive layer; see generallylayer 1350 of FIG. 47) disposed on the first major surface, the secondmajor surface, or both the first major surface and the second majorsurface. In one or more embodiments, the conductive layer partially orwholly covers the major surface on which it is disposed, such asoverlaying at least 20% of the respective surface, at least 40%, atleast 60%, at least 80%. In other words, the conductive layer may form acontinuous layer on the entire area of the surface on which it isdisposed or may form a discontinuous layer on the surface on which it isdisposed. The conductive layer may form a pattern that may be repeatingor periodic, such as for not-yet-singulated semiconductor componentsformed on a tape. In one or more embodiments, the sintered article mayinclude one or more additional layers disposed on top of the conductivelayer or between the conductive layer and the sintered article, and/orintermediate to the conductive layer and the tape (or other sinteredarticle as disclosed herein). Such one or more additional layers maypartially or wholly covers the surface on which it is disposed (i.e., amajor surface of the sintered article or the conductive layer), such asaccording to the percentages described above for the conductive layer.In other words, the one or more additional layers may form a continuouslayer on the entire area of the surface on which it is disposed or mayform a discontinuous layer on the surface on which it is disposed. Theone or more additional layers may form a pattern that may be repeatingor periodic. In some embodiments, the one or more additional layers mayalso be conductive layers, dielectric layers, sealing layers, adhesivelayers, surface-smoothing layers, or other functional layers. In someembodiments, the conductive layer and, optionally, the one or moreadditional layers, may be present in sintered articles having athickness of less than 1 mm, about 0.5 mm or less, about 300 micrometersor less, about 150 micrometers or less, about 100 micrometers or less orabout 50 micrometers or less. Accordingly, the layers and the sinteredarticle may be flexible, and/or may be rolled onto a roll or spool asdisclosed herein.

In some embodiments, the sintered article may include two or more of aplurality of vias, a conductive layer and one or more additional layers.

In one or more embodiments, system 10 for producing a sintered tapearticle may include a fabrication system for further processing a greentape, partially sintered articles, and/or sintered articles describedherein for use in a microelectronics article. In one or moreembodiments, the fabrication system may be disposed downstream of thebinder burn out furnace 110 but upstream of the sintering station 38 toprocess tape without binder, or after the sintering station 38 toprocess a partially sintered article or before the furnace 110 toprocess the green tape, which would then be sintered as otherwisedescribed herein. In one or more embodiments, the fabrication system maybe disposed downstream of the sintering station 38 but upstream of theuptake system 42 to process a sintered article. In one or moreembodiments, the fabrication system may be disposed downstream of theuptake reel 44 but upstream of the reel 48, to process a sinteredarticle. In one or more embodiments, the fabrication system may bedisposed downstream from the reel 48 to process a sintered article. Insuch embodiments, the fabrication system would process the green tapematerial, partially sintered article or sintered article when it iscontinuous (and not discrete). Other configurations are possible toprocess the sintered article as a discrete article.

In one or more embodiments, the fabrication system may expose at least aportion of the green tape material, partially sintered article orsintered article to a mechanism for forming vias, such as laser energy,or a drill. The fabrication system of one or more embodiments usinglaser energy to create the vias may include a hug drum (see generallyvacuum drum 25 of FIG. 6) having a surface with a curvature, wherein thehug drum pulls the green tape material, partially sintered article orsintered article to the match its curvature to facilitate formation ofthe vias on the major surface of the sintered article. In one or moreembodiments, the hug drum would facilitate focus of the laser beam onthe major surface of the green tape material, partially sintered articleor sintered article.

In one or more embodiments, the vias may be created by mechanical means.For example, the fabrication system may include a flat plate on which aportion of the green tape material, partially sintered article orsintered article is temporarily secured. In this manner, one majorsurface of the green tape material, partially sintered article orsintered article is in contact with the flat plate. The conveyance ofthe green tape material, partially sintered article or sintered articleto the fabrication system may use a step and repeat motion, accelerationor deceleration velocity, or continuous velocity to allow for a portionof the sintered article to be temporarily secured to the flat plate. Inone or more embodiments, a vacuum may be used to temporarily secure aportion of the green tape material, partially sintered article orsintered article to the flat plate.

In one or more embodiments, fabrication system may form vias bymechanically separating a portion of the green tape material, partiallysintered article or sintered article. In one or more embodiments, thefabrication system may include the use of photolithography, withsolvents or acids to remove a portion of the green tape material,partially sintered article or sintered article. In such embodiments,when the fabrication system is applied to green tape material orpartially sintered articles, the fabrication system may include acontrol mechanism for controlling the scale and pattern scale of thevias, due to shrinkage of the green tape material or partially sinteredarticle when it is fully sintered. For example, the control mechanismmay include a sensor at the outlet of the sintering station 38 thatmeasures the distance between the vias and the spacing of the vias andfeedback this information to the fabrication system for adjustment. Forexample, if the fabrication system was forming vias having a diameter ofabout 75 micrometers, and a distance or pitch of 500 micrometers betweenthe vias, and it was assumed that the full sintering shrinkage from thegreen tape material to the sintered article was 25%, then thefabrication system would or may adjust to form the vias in the greentape material to have a pitch of 667 microns and a diameter of about 100micrometers. After processing, the full sintering shrinkage is measuredto be 23% then, the fabrication system could further adjust to thecorrect spacing for the vias in the green tape material would be 649microns, to accommodate for 23% full sintering shrinkage. Vias in someembodiments have a widest cross-sectional dimension (coplanar with asurface of the sheet or tape) that is at least 250 nm, such as at least1 μm, such as at least 10 μm, such as at least 30 μm, such as at least50 μm, and/or no more than 1 mm, such as no more than 500 μm, such as nomore than 100 μm. In some embodiments, the vias are filled with anelectrically conductive material, such as copper, gold, aluminum,silver, alloys thereof, or other materials. The vias may be laser cut,laser and etchant formed, mechanically drilled, or otherwise formed. Thevias may be arranged in a repeating pattern along a sheet or tape, whichmay later be singulated into individual electronics components.

FIG. 104 shows an example in cross-section of a stacked arrangement 810of ceramic sheets 812 with vias 814 extending to metal layers 816.Fiducial 818 may help align the sheets 812.

The system 10 described herein provides other ways to control viaspacing during the sintering process. For example, tension in theprocessing direction 14 during sintering can stretch the sinteringarticle and bias the sintering shrinkage. This tension can increase thespacing of the vias in the processing direction 14, effectively reducingthe sintering shrinkage in the processing direction 14. Differentialsintering in the processing direction 14 as opposed to the directionperpendicular to the processing direction 14 has been observed, and canbe in a range from about 2% to about 3%, when tension is applied.Accordingly, some otherwise round vias may be oval or oblong.

The size and shape of the vias can be controlled and adjusted with acombination of the sintering shrinkage along the direction parallel tothe processing direction 14, sintering shrinkage across the directionperpendicular to the processing direction 14, tension in the twodirections and the shape of the sintering station 38 and/or through useof air bearings to transport the green tape material, the partiallysintered article or the sintered article while sintering or hot.

In one or more embodiments, ceramic material may be added at any stepwithin the system 10 to decrease the sintering shrinkage. Ceramicmaterial can be added by ink jet print heads, which can apply suchceramic material uniformly to a porous partially sintered article orsintered article, while such articles have open porosity. In one or moreembodiments, small amounts of ceramic material can be added to theporous partially sintered article or sintered article by printing.Lasers, photolithography, ink jets, atomic layer deposition, and someprinting and other processing means can be accomplished from the innerradius of a curved air bearing or with a sectioned hug drum with openareas for the exposure of the partially sintered article or sinteredarticle to the processing equipment. Accordingly, tape or other articlesas disclosed herein may be or include a portion thereof of two or moreco-fired inorganic materials (e.g., ceramics or phases), such as whereone of the materials infiltrates and fills pores of the other material.In contemplated embodiments, the filling/infiltrating material may bechemically the same as the porous material, but may be distinguishablein terms of crystal content (e.g., grain size, phase).

In one or embodiments, vias can be formed on sintered article havingwith patterns of conductor layers on one or both sides. The conductorlayer(s) can be printed or patterned (screen printing, electrolessdeposition, etc.) after via formation and final sintering. In one ormore embodiments, the conductor layer(s) but can also be printed ordeposited prior to final sintering of the sintered article. In somesintering processes that sinter only discrete pieces (and not continuousribbons) small sheets (e.g., having length and width dimensions of about20 cm by 20 cm), the conductor layer(s) are printed after via formation,and/or but on green tape material only. For multi-layer substrates,individual green tape layers are or may be aligned and laminated, withsome multi-layer substrates using as many as 30-40 green tape layers.Alumina with tungsten, molybdenum or platinum conductors may beco-sintered and form low firing ceramic packages based on cordierite(glass ceramics) using conductors based on copper. In some embodimentsdescribed herein, conductive layer(s) may be formed (i.e., by printingor deposition) prior to the final sintering step, and the technologydisclosed herein may help control the dimensions of the vias andconductor patterns during the sintering steps.

Moreover, the continuous sintering processes and system 10 offers meansto control the vias spacing and patterns and conductive layer(s)patterns in terms of spacing during the sintering process. Tension inthe processing direction during the sintering can stretch the green tapematerial, partially sintered article, or sintered article and/or biasthe sintering shrinkage as disclosed above. This tension can increasethe vias spacing and patterns and conductive layer(s) patterns in theprocessing direction, effectively reducing the sintering shrinkage inthe process direction. Differential sintering in the processingdirection versus the direction perpendicular to the processing directionmay range from about 2% to about 3%, such as where tape is stretched inthe processing or lengthwise direction.

Controlled curvature sintering station 38 or curved air bearings can beused to transport the green tape material, partially sintered article,or sintered article in the processing direction 14 and may prevent thegreen tape material, partially sintered article, or sintered articlefrom having excessive curvature across the width of the green tapematerial, partially sintered article, or sintered article. If there is amild cross-ribbon- or sheet-curvature, the tension in the directionparallel to the processing direction may provide some tensionperpendicular to the processing direction, controlling or limitingdistortion.

Providing tension to the direction perpendicular to the processingdirection 14 can be difficult, particularly at the temperatures wherethe sintered article is plastically deformable and/or is sintering andplastically deformable. Rollers (see, e.g., FIG. 88B) angled away from adirection parallel to the processing direction 14 in such regions of thesystem 10 (or particularly sintering station 38) can apply some tensionperpendicular to the processing direction 14 (e.g., in a widthwisedirection of tape). This tension may increase the spacing of the viasperpendicular to the processing direction 14, effectively reducing thesintering shrinkage perpendicular to the processing direction 14.

Fiducial marks for alignment can be made by lasers, mechanical means,chemical means such as slight composition changes with visible results.These marks help align further processing steps such as conductorprinting, patterning, and/or laminating.

Another aspect of this disclosure pertains to a multi-layer sinteredarticle having a width of about 1 mm or greater, 1 cm or greater, 5 cmor greater, 10 cm or greater, or 20 cm or greater, with a length of 1 mor greater, 3 m or greater, 5 m or greater, 10 m or greater, or 30 m orgreater, where the sintered article has a thickness of less than 1 mm,less than about 0.5 mm, less than about 300 microns, less than about 150microns, less than about 100 microns. In one or more embodiments, thesintered article has a crystalline ceramic content of more than 10% byvolume, more than 25% by volume, more than 50% by volume, more than 75%by volume, or more than 90% by volume. The article has at least twolayers of sintered articles and may have more than 40 such layers. Thesintered article layers have at thickness of 150 microns or less, 100microns or less, 75 microns or less, 50 microns or less, 25 microns orless, 20 microns or less, 15 microns or less, 10 microns or less, 5microns or less, and/or such as at least 3 microns (i.e. at least 3micrometers). In one or more embodiments, the sintered article layersneed not be the same composition and some such layers include glass. Insome embodiments, such glass layers may include 100% glass, such as atleast 100% amorphous silicate glass.

In one or embodiments, the multi-layer sintered article includes aplurality of vias, conductive layer(s) and/or optional additionallayers, as described herein with respect to microelectronics articles.

In one or more embodiments, the system 10 may include a process and anapparatus to make such multi-layer sintered articles. The multi-layercan be made by casting or web coating multiple layers of green tapematerial (i.e., with ceramic particles with polymer binder) over oneanother. The multi-layer green tape material structure may then beprocessed through the system 10 as described herein. In one or moreembodiments, the multi-layer green tape material structure can also beformed by laminating multiple green tapes with ceramic particles at nearroom temperature in a continuous fashion and then by feeding thelaminated tapes into the system 10. Partially sintered articles can alsobe laminated together with minor pressure in the sintering station 38.The pressure can be caused by having a mild curvature in the sinteringstation 38 that the partially sintered articles are drawn across. Eachpartially sintered article can have its own tensioning and payout speedcontrol means. Each partially sintered article can have fiducial marksto assist alignment of the articles. Tension and payout speed can beused to match sintering shrinkage from article to article to align viasand conductors from article to article. If the fiducial marks are notaligned as the multi-layer article exits the furnace, the layer payoutspeeds and/or tensions can be adjusted to bring the layers back intoalignment. Additional pressure normal to the length and width ofmulti-layer articles can be provided by rollers at high temperature asdescribed above.

As electrical conductors and ceramic materials in multi-layer electronicsubstrates may not have the same thermal expansion coefficient, somedesigns may provide for an overall stress reduction (balance) for “top”side to “bottom” side of the multi-layer sintered articles. In essencesuch designs have a similar amount of metal or ceramic on the top andbottom of the multi-layer, such as by mirroring the layers about acentral plane in the respective stack. With thin ceramic layers, astructure that is not stress/CTE balanced may experience deformation ofthe ceramic and/or curling of the overall stacked structure.

In one or more embodiments, a circuit board for electronics comprises asintered article, as described herein, having electronic conductorspatterned on it. The conductors for the circuit board may be directlyprinted onto the green tape material, the partially sintered article, orthe sintered article and/or may be printed onto a coating(s) or layer(s)bonded to the green tape material, the partially sintered article, orthe sintered article, such as an adhesion promoting layer, a surfacesmoothing layer, and/or other functional layers. The printing can befrom a direct screen printing, electroless deposition and pattering,lithography, using a silicone carrier intermediate between the patternformation and the application of the pattern on the sintered article bygavure patterning rollers, and/or by other processes.

The conductors for the circuit board can be directly printed on thepartially sintered article, after an intermediate firing step but beforethe final sintering, and/or printed onto coatings thereon. Porosity inthe partially sintered article or sintered article can improve adhesionof the conductor print or pattern. The printing can be from a directscreen printing, lithography, using a silicone carrier intermediatebetween the pattern formation and the application of the pattern on theceramic by gavure patterning rollers, or other processes.

One aspect of the process and apparatus may be to use a hug drum whilesimultaneously patterning the long continuous porous ceramic ribbon orsheet. The hug drum pulls the ceramic ribbon or sheet to match thecurvature on the surface of the drum, making printing of the conductorpattern less difficult. Photolithography can also be used with solventsor acids to etch or wash away some of the conductor pattern on the greenribbon or sheet prior to final sintering, photolithography can beaccomplished on a hug drum. When the conductor is patterned prior tofinal sintering, a means to control the pattern, size, scale, or pitchwith the sintering shrinkage is advisable. Unfortunately, sinteringshrinkage of a ceramic ribbon or sheet can vary by a percent or morefrom one continuous green ribbon (or sheet) to another continuous greenribbon (or sheet), sometimes even within a single green ribbon or sheet.One method to insure an accurate spacing of the conductor pattern is tohave a sensor at the outlet of the final sintering step and measure thedistance of the conductor pattern spacing. This information can be feedto the printing pattern means (e.g., laser, drill, punch, etch system),photolithography exposure means (e.g., radiation or light source, mask),to adjust the conductor pattern in the pre-final sintered ribbon orsheet to match the current sintering shrinkage. (The length of theribbon or sheet between the measuring means and the “patterning” meansmay not be perfectly precise, however may be more accurate than eitherbatch sintering with a periodic kiln or use of a tunnel kiln, such aswhere a great deal of final product may be lost due to inaccuracy.)

Continuous sintering (e.g., roll to roll sintering, continuous firedceramic) offers another means to control the via spacing during thesintering process. Tension in the web transport direction (i.e.lengthwise direction for a tape) provided during the sintering canstretch the sintering article (e.g., ribbon or sheet) and/or bias thesintering shrinkage. This tension can increase spacing of the conductorpattern in the ribbon or sheet transport direction, effectively reducingthe sintering shrinkage in the ribbon transport direction. Differentialsintering in the ribbon transport direction versus the directionperpendicular to the ribbon transport direction has been observed, up to2 to 3% when tension is applied.

Photolithography, ink jets, atomic layer deposition, some printing andother processing means can be accomplished from the inner radius of acurved air bearing or with a sectioned hug drum with open areas for theexposure of the ceramic ribbon or tape to the conductor patteringprocessing equipment.

Alumina with tungsten, molybdenum or platinum conductors may beco-sintered with other inorganic materials disclosed herein and form lowfiring ceramic packages based on cordierite (glass ceramics) usingconductors based on copper.

Controlled curvature kiln furniture or curved air bearings, that theceramic ribbon or web with a conductor pattern is pulled through orover, can keep the ceramic ribbon or sheet with a conductor pattern fromhaving excessive curvature across the short length of the ribbonperpendicular to the ribbon transport direction in some suchembodiments.

Providing tension to the direction perpendicular to the ribbon transportdirection, (cross web direction), can be difficult, particularly at thetemperatures where the ceramic ribbon with conductor pattern isplastically deformable or is sintering and plastically deformable.Rollers angled away from parallel to the ribbon transport direction inthe hot zones of the furnace can apply some tension perpendicular to theribbon transport direction. This tension can increase the spacing of thevias perpendicular to the ribbon transport direction, effectivelyreducing the sintering shrinkage perpendicular to the ribbon transportdirection. The size and pitch of the conductor patterns can becontrolled and adjusted with a combination of the sintering shrinkagealong the direction parallel to the ribbon transport direction (longlength of the ceramic ribbon), sintering shrinkage across the directionperpendicular to the ribbon transport direction, tension in the twodirections and the shape of the kiln furnace and/or air bearing that theceramic ribbon or sheet is on while sintering or hot.

Fiducial marks for alignment can be made by lasers, mechanical means,chemical means such as slight composition changes with visible results.These marks help align further processing steps such as conductorprinting/patterning and laminating.

Multi-layer structures with ceramic and conductor may be bonded at hightemperature from final sintered conductor plus ceramic sheets or ribbonswith fewer layers, even from sheets with only a single ceramic plusconductor layer.

Thin circuit boards with ceramic insulator layers benefit from having astress balance from top to bottom. This may be accomplished by having apatch or pattern of material printed on the side opposite to the desiredconductor pattern that can alleviate the coefficient of thermalexpansion CTE or thermal expansion related stress between the conductorand ceramic (and sometimes a sintering differential stress between theconductor and the ceramic). This may take the form of a second conductorlayer with a similar thickness and mass of material on the bottom of theboard, which balances the CTE stress (and sintering differential stress)from top to bottom leaving the circuit board almost flat, rather thancurled.

As the multi-layer structure and/or the circuit board becomes thicker,it becomes stiffer after full sintering. Particularly with 1 mm, 0.5 mm,and 250 micron thickness ceramic and conductor structures, rolling thearticle on small rolls of 30 to 7.5 cm in diameter can be problematic.Means for cutting the continuously sintered articles by laser, diamondsaw, abrasive jet, water jet and other techniques can be adapted to thecontinuous sintering apparatus, such as where individual or groups ofstructures may be cut into sheets. The cutting apparatus may be added tothe exit of the final sintering furnace, and the cutting means wouldtravel or interface with the long article, such as while it is exitingthe furnace.

Referring to FIGS. 56 and 57, a process for initiation of sintering andthreading of green tape 20A through binder removal station 34A andthrough sintering station 38A of a system 1500A for producing a sinteredtape article is shown according to an exemplary embodiment. In general,system 1500A is substantially the same as and functions the same assystem 10 discussed above, except for slightly different, alternativereel arrangements/positioning in separation system 12A, tension controlsystem 32A and uptake system 42A.

To initiate the reel to reel transfer of tape material from source reel16A to uptake reel 44A, green tape 20A needs to be threaded through thechannels of binder removal station 34A and through sintering station 38Ain order for the green tape 20A to be connected to uptake reel 44A whichapplies the tension to pull green tape through binder removal station34A and through sintering station 38A. Similarly, if during operation ofbinder removal station 34A and sintering station 38A the tape materialbreaks (which may occur following binder removal), the tape materialneeds to be threaded through binder removal station 34A and then throughsintering station 38A while these stations are at full operatingtemperature. Applicant has determined that threading, particularly whenbinder removal station 34A and sintering station 38A are at temperature,can be particularly challenging due to the difficulty in threadingunbound tape 36 (shown in FIG. 3) (i.e., the self-supporting tapematerial following removal of the organic binder) through sinteringstation 38A following binder removal. Thus, it should be understood thatwhile the discussion of the threading process and system discussedherein relates primarily to threading green tape 20A, the threadingprocess can be used to thread a variety of tape materials, includingunbound tape 36 (shown in FIG. 3) and/or partially sintered tapematerial, through a sintering system such as system 10 or system 1500A.

As will be discussed in more detail below, Applicant has developed aprocess utilizing a threading material or leader to pull green tape 20Athrough binder removal station 34A and sintering station 38A in order toinitiate the reel to reel processing discussed above. In suchembodiments, the threading material is passed through sintering station38A and binder removal station 34A, and the leader is coupled to thegreen tape 20A on the upstream or entrance side of binder removalstation 34A.

Tension is then applied from the uptake reel 44A through the leader togreen tape 20A to begin the process of moving green tape 20A throughbinder removal station 34A and through sintering station 38A. While avariety of approaches to threading green tape through binder removalstation 34A and through sintering station 38A may allow for sintering ofgreen tape to be achieved (e.g., manual threading), Applicant hasdetermined that the leader based threading process discussed hereinprovides high quality/low warp in the sintered tape material even at theleading edge of the sintered material. This improved product qualitydecreases product waste, improves process efficiency by eliminating theneed for handling/removal of warped sections on the green tape andimproves integrity of the wind of sintered material on uptake reel 44Adue to the shape consistency along the length of the sintered tapematerial. In addition, in the context of hot threading (e.g., threadingwhen binder removal station 34A and sintering station 38A are attemperature), Applicant has found that use of the leader based processdiscussed herein provides an efficient way to support and pull theleading edge of the delicate, unbound portion of tape material (e.g.,unbound tape 36 shown in FIG. 3 and discussed above) following exit fromthe binder removal station 34A until sintering has occurred duringtraversal of the sintering station 38A.

In the embodiment shown in FIGS. 56 and 57, threading material, shown asleader 1502A, is threaded from uptake reel 44A, in the reverse directionthrough the channels of both sintering station 38A and of binder removalstation 34A such that a first section, shown as end section 1504A, ofthe leader 1502A is positioned outside of entrance opening 116A ofbinder removal station 34A. In this arrangement, as shown in FIG. 56,leader 1502A is a single contiguous piece of material positioned suchthat leader 1502A extends the entire distance from uptake reel 44A andall of the way through sintering station 38A and binder removal station34A.

Green tape 20A is moved from source reel 16A (e.g., via unwinding ofgreen tape 20A from the reel as discussed above) toward entrance opening116A of binder removal station 34A such that a leading section 1506A ofgreen tape 20A is located adjacent to and overlapping end section 1504Aof leader 1502A. As shown in FIG. 57, after positioning leading section1506A of green tape 20A and end section 1504A of leader 1502A adjacenteach other, leading section 1506A of green tape 20A and end section1504A are coupled or bonded together upstream of binder removal station(e.g., between entrance opening 116A of binder removal station andsource reel 16A in the processing direction 14A). This forms a join orbond between leader 1502A and green tape 20A at the overlapped section.

Once leader 1502A is coupled to green tape 20A, a force is applied to aportion of leader 1502A located outside of (e.g., downstream from)binder removal station 34A and sintering station 38A such that leader1502A and green tape 20A are pulled in the processing direction 14Athrough binder removal station 34A and sintering furnace 38A. In thespecific embodiment shown in FIG. 56, a second or downstream end 1508Aof leader 1502A is coupled to uptake reel 44A, and the force generatedby rotation of uptake reel 44A provides the force for moving/pullingleader 1502A and green tape 20A through binder removal station 34A andsintering furnace 38A. In some embodiments, Applicant has found thatprocessing speeds of about 3 inches/minute (e.g., the speed that thetape material is moved through system 1500A) are used during the threadup process, and in specific embodiments, this speed may be increased toabout 6 inches/minute for sintering processing once the join betweenleader 1502A and green tape 20A has traversed binder removal station 34Aand sintering furnace 38A.

Thus, through the use of leader 1502A, the downstream or rewind side ofsystem 1500A is initially coupled to the upstream or unwind side ofsystem 1500A, allowing for the initiation of reel to reel sintering ofthe material of green tape 20A. In addition, by providing this initialthreading of binder removal station 34A and sintering station 38A viaconnection between the same unwind and uptake systems that advance greentape 20A during sintering processing, the leader-based threading processdiscussed herein is able to establish the proper tension and velocityfor the entire length of green tape 20A that traverses binder removalstation 34A and sintering station 38A, including the leading section1506A of green tape 20A at the overlapped location. Further, byproviding a horizontal pulling force through leader 1502A, the leaderbased process discussed herein allows for threading through thehorizontally orientated channels of binder removal station 34A andsintering station 38A, which can otherwise be difficult (particularlygiven the delicate nature of the tape material following binderremoval).

As discussed above in detail regarding system 10, binder removal station34A is heated to remove or burn off binder from green tape 20A, andsintering station 38A is heated to cause sintering of the inorganicmaterial of green tape 20A. In one potential use of the threadingprocess discussed herein, binder removal station 34A and/or sinteringstation 38A are already at their respective operating temperatures whenleader 1502A is threaded. This is the case when leader 1502A is used tothread green tape 20A following a break in the material during reel toreel sintering. In another potential use of the threading processdiscussed herein, binder removal station 34A and/or sintering station38A are at a low temperature (e.g., below their respective operatingtemperatures, off at room temperature, etc.) when leader 1502A isthreaded through. This is the case when leader 1502A is used to threadgreen tape 20A during initial start-up of system 1500A.

As discussed in more detail above, following the initial movement of thejoin or overlap between leader 1502A and the leading section 1506A ofgreen tape 20A through binder removal station 34A and sintering furnace38A, green tape 20A is continuously unwound from source 16A and movedthrough stations 34A and 38A, forming the length of sintered material asdiscussed above. Following sintering the sintered material is wound ontouptake reel 44A. In one embodiment, leader 1502A is decoupled from thesintered tape material once leading section 1506A of green tape 20Aexits from sintering station 38A, and prior to winding of the sinteredtape material onto uptake reel 44A. In another embodiment, leader 1502Ais wound onto uptake reel 44A along with the sintered tape materialforming the innermost layers of the reel including the sinteredmaterial.

In various embodiments, leader 1502A is an elongate and flexible pieceof material that is able to resist the high temperatures of binderremoval station 34A and sintering station 38A. In the coupling processshown in FIG. 57, leading section 1506A of green tape 20A overlaps endsection 1504A of leader 1502A forming overlap section 1512A. In thisarrangement, a lower surface of green tape 20A faces and contacts anupper surface of leader 1502A. In this arrangement, by positioning greentape 20A on top of leader 1502A, leader 1502A acts to support leadingsection 1506A of green tape 20A through binder removal station 34A andsintering furnace 38A.

In some embodiments, an adhesive material 1510A is used to form a bondjoining leader 1502A to green tape 20A. As shown in FIG. 57, in somesuch embodiments, adhesive material 1510A is located on the uppersurface of leader 1502A and forms a bond to the lower surface of greentape 20A. As discussed in more detail below, in various embodiments,Applicant has identified that the matching of various characteristics,(e.g., coefficient of thermal expansion (CTE) of the materials formingadhesive 1510A, leader 1502A and green tape 20A), facilitatesmaintenance of the bond between leader 1502A and the tape material,particularly during traversal of the high temperatures of sinteringstation 38A. Further, a strong bond between leader 1502A and green tape20A allows for the desired level of tension to be applied to leader1502A and transmitted through the bond provided by adhesive 1510A, togreen tape 20A. As discussed herein, Applicant has found that a low(e.g., gram level), but consistent tension applied to the tape materialduring sintering reduces warp that may otherwise be formed across thewidth of the tape during sintering.

In various embodiments, Applicant has determined that the volume ofadhesive material 1510A used as well as the shape of the appliedadhesive material 1510A on leader 1502A influences the properties of thebond formed between leader 1502A and green tape 20A. In specificembodiments, adhesive material 1510A is a small volume (e.g., about 0.1mL of an alumina-based adhesive material). In one embodiment, adhesive1510A is used to bond a leader 1502A to an unsintered green tapematerial 20A, and in such embodiments, Applicant has found that a rounddot of adhesive 1510A works well. Applicant hypothesizes that the roundgeometry helps to distribute the thermal and mechanical stresses inducedby cement and tape shrinkage and CTE mismatch (if any) between thematerials of leader 1502A, adhesive 1510A and green tape 20A. In anotherembodiment, adhesive 1510A is being used to bond a leader 1502A to atape of partially sintered material, and in such embodiments, Applicantbelieves that a line of adhesive 1510A extending across the width ofleader 1502A works well. Applicant hypothesizes that the line geometryacts to apply an even constraint across the web as it moves through thesintering station.

In specific embodiments, binder removal station 34A is operated toremove liquid and/or organic components from adhesive 1510A (as well asfrom green tape 20A) as the overlapped section 1512A between leader1502A and green tape 20A traverses binder removal station 34A. Applicantbelieves that various properties of the adhesive material 1510A and ofgreen tape 20A relate to the likelihood that the bond formed by adhesivematerial 1510A will break during traversal of binder removal station 34Aand sintering station 38A. Applicant hypothesizes that the temperatureprofile through binder removal station 34A can cause the organicmaterial in green tape 20A to soften and even melt prior to evolvingfrom the tape, which can help to limit the stress intensity around thecement join as the individual components begin to change shape/size dueto shrinkage and thermal expansion. Applicant hypothesizes that allowinggreen tape to ‘deform’ or re-form around the location of adhesive 1510A,prior to losing its elastic/plastic properties helps to decrease defectsand improves the quality of the bond formed by adhesive 1510A. Similarlythis elastic/plastic property may also allow for venting of liquids andorganic materials from adhesive 1510A, which may otherwise cause anincrease in pressure between leader 1502A and green tape 20A. Thisincrease in pressure may cause the bond to fail or the gas build up mayrupture through green tape 20A.

In specific embodiments, the tension applied during the process ofpulling the overlapped section or join between leader 1502A and greentape 20A may be changed or increased as overlap section 1512A traversesbinder removal station 34A and/or sintering station 38A. In a specificembodiment, a low level of tension, e.g., of below 25 grams, is providedinitially, during traversal of overlap section 1512A across binderremoval station 34A, and then tension is increased as the overlapsection 1512A traverses sintering station 38A. In a specific embodiment,tension on the order of 25 grams or more is applied once overlap section1512A and adhesive material 1510A reaches the center of sinteringstation 38A. Applicant believes that tension at this point can beincreased without separation of the bond between leader 1502A and greentape 20A because of the sintering of material of green tape 20A that hasoccurred at this point. Applicant believes that applying a high level oftension too early, before the strength has had a chance to develop willgenerally lead to failure of the bond formed by adhesive 1510A.

In various embodiments, coupling and/or support between leader 1502A andgreen tape 20A is enhanced by various levels of overlap between leader1502A and green tape 20A. As can be seen in FIG. 57, the greater theoverlap between leader 1502A and green tape 20A, the greater the amountof support provided by leader 1502A to green tape 20A. Similarly, thelevel of overlap between leader 1502A and green tape 20A relates to theamount of friction-based coupling between leader 1502A and green tape20A, which may supplement the bonding provided by adhesive 1510A. Inembodiments utilizing adhesive 1510A, Applicant has found that anoverlap section 1512A having a length measure in the processingdirection 14A of between one to five inches has performed well. In someembodiments, coupling between leader 1502A and green tape 20A may beprovided by friction only (e.g., without adhesive 1510A) and in suchcases the length of the overlap section 1512A in the processingdirection 14A may be greater than five inches, such as greater than 10inches, between 10 inches and 30 inches, about 24 inches, etc.

In various embodiments, Applicant has identified a number of materialcombinations for leader 1502A, green tape 20A, and adhesive 1510A thatprovide the threading properties/functionality discussed herein. Ingeneral, leader 1502A is formed from a material that is different in atleast one aspect from green tape 20A. In some such embodiments, leader1502A is formed from the same material type as the inorganic grains ofgreen tape 20A but has a different (e.g., higher) degree of sinteringthan the inorganic material of green tape 20A. In some such embodiments,leader 1502A is an elongate tape of sintered ceramic material, and greentape 20A supports unsintered or less sintered grains of the same type ofceramic material.

In some other embodiments, leader 1502A is formed from an inorganicmaterial that is different from the material type of the inorganicgrains of green tape 20A. In a specific embodiment, leader 1502A isformed from a ceramic material type that is different than the ceramicmaterial type of the inorganic grains of green tape 20A. In some otherembodiments, leader 1502A is formed a metal material, while theinorganic grains of green tape 20A are a ceramic inorganic material.

Applicant has found that the coupling arrangements shown in FIG. 57 anddescribed herein provides a level of coupling between leader 1502A andgreen tape 20A that allows for good transmission of force/tension fromleader 1502A to green tape 20A without significant risk of decoupling.Further, Applicant has found that the risk of decoupling and warp causedduring sintering can be decreased by selecting materials for leader1502A, adhesive 1510A and the inorganic grain material of green tape 20Athat have relatively similar coefficients of thermal expansion (CTEs) aseach other. In various embodiments, the CTE of the material of leader1502A is within plus or minus 50 percent of the CTE of the inorganicmaterial of green tape 20A, specifically within plus or minus 40 percentof the CTE of the inorganic material of green tape 20A, and morespecifically within plus or minus 35 percent of the CTE of the inorganicmaterial of green tape 20A. Similarly, in various embodiments, the CTEof the material of leader 1502A is within plus or minus 50 percent ofthe CTE of adhesive material 1510A, specifically within plus or minus 40percent of the CTE of adhesive material 1510A, and more specificallywithin plus or minus 35 percent of the CTE of adhesive material 1510A.

Leader 1502A can be formed from a variety of suitable materials. In someembodiments, leader 1502A is formed from a sintered ceramic material,and in other embodiments, leader 1502A is formed from a metal material.In some embodiments, Applicant has found that using a porous ceramicmaterial for leader 1502A increases the ability of adhesive material1510A to bond to leader 1502A. Applicant believes that the porosity ofleader 1502A allows adhesive material 1510A to bond more easily than ifthe leader had a less porous or polished surface. In specificembodiments, leader 1502A may be a platinum ribbon or a fully sinteredceramic material, such as alumina or yttria stabilized zirconia (YSZ)

In specific embodiments, leader 1502A is sized to allow handling andcoupling to green tape 20A. In specific embodiments, leader 1502A has awidth that substantially matches (e.g., within plus or minus 10%) of thewidth of green tape 20A. In specific embodiments, leader 1502A has athickness of between 5 μm and 500 μm and more specifically a thicknesswithin the range of 20 to 40 μm. Further, leader 1502A has a lengthsufficient to extend from uptake reel 44A through both sintering station38A and binder removal station 34A and thus the length of leader 1502Avaries with the size of system 1500A.

While FIGS. 56 and 57 generally show leader 1502A as a long, thin, flatsection of sintered ceramic material, leader 1502A may take other forms.For example, in one embodiment, leader 1502A may be a ceramic board witha long length of platinum wire which is cemented to the green tape. Inanother embodiment, leader 1502A may be a length of ceramic fiber ropeor ceramic fiber twine.

Adhesive material 1510A can be formed from a variety of suitablematerials. In some embodiments, adhesive material 1510A is a ceramicadhesive material. In specific embodiments, adhesive material 1510A isan alumina-based adhesive material, such as alumina-based adhesive #C4002 available from Zircar Ceramics.

Referring to FIGS. 58-65, various systems and processes for bendingunbound tape 36B in the longitudinal or lengthwise direction duringsintering are shown and described. In general, Applicant has determinedthat one of the unexpected challenges when sintering wide, thin andcontinuous lengths of unbound tape 36B is ensuring that the finalsintered tape 40B has high levels of cross-width flatness. A high levelof cross-width flatness is desirable when using the sintered tapematerial discussed herein in a number of applications, such assubstrates for thin-film circuitry, thick film circuitry, solid-statelithium ion batteries and the like.

Some continuous tape sintering processes may be susceptible to certainflatness distortions (e.g., cross-width bowing, edge wrinkle, bubbleformation, etc.) believed to be formed due to creation in-plane stresseswithin the tape material during sintering. For example, Applicant hasfound that due to a variety of factors, such as variations in ceramicparticle density in unbound tape 36B, large temperature differentialswithin the tape material along the length of the systems (e.g., whichmay be in excess of 1000 degrees C. due to the continuous nature of thesystems and processes discussed herein), processing speeds, etc.,contribute to the generation of the in-plane stresses during sintering,which in turn may induce buckling in the absence of a countervailingapplication of force in a manner that allows for release of thesein-plane stresses.

For example, an alumina tape undergoing continuous sintering via thesystems discussed herein may have regions simultaneously at roomtemperature and at the maximum sintering temperature. There may also beregions of the tape beginning the sintering process where shrinkage isminimal and areas of the tape where sintering is nearly complete, wherethe shrinkage exceeds 8% or even 10% on a linear basis. The gradient inshrinkage and temperature may be sources of complex, biaxial stressesthat may induce distortions, such as by curling and wrinkling, even in atape that enters the sintering station having a level of flatness. Suchdistortions may then become frozen into the sintered tape followingcooling, thereby degrading its potential uses.

As will be discussed in detail below, Applicant has determined thatstresses that may cause flatness distortions can be at least in partcounteracted by inducing a lengthwise or longitudinal curve in the tapeduring sintering. During sintering, the tape material plasticallyrelaxes and deforms to the shape of the induced lengthwise bend, whichgenerates forces within the tape material that tends to reduce in-planestresses that may otherwise occur, and a result may be to produce asintered tape with a high level of cross-width flatness. Applicantbelieves that by utilizing lengthwise bending during sintering, aflatter sintered tape can be produced despite variations in green tapeparticle density and high production speed.

Further, in at least some embodiments, the flattening process discussedherein produces flat, thin sintered articles while avoiding/limitingsurface contact and the resulting surface defects and scratches commonwith contact/pressure-based flattening devices, such as may beexperienced when pressing a material between cover plates duringsintering. As will be shown below, Applicant has developed a number ofsystems and processes for inducing the longitudinal bend that leave atleast one major surface of the tape untouched during sintering, and someprocesses that leave both upper and lower (major) surfaces of the tapeuntouched during sintering. Applicant believes that other ceramicsintering processes may not achieve the high levels of cross-widthflatness, in a continuous sintering process or with the limited degreeof surface contact provided by the system and processes discussedherein.

Referring to FIG. 58, a process and system for producing a highflatness, sintered continuous tape is shown. Specifically, FIG. 58 showsa system 1600B for producing a sintered tape article, according to anexemplary embodiment. In general, system 1600B is generally the same asand functions the same as system 10 discussed above, except that system1600B includes a sintering station 38B that includes a bending system1602B located within sintering station 38B. In general, bending system1602B is configured or arranged to induce a radius of curvature along alengthwise or longitudinal axis of unbound tape 36B while tape 36B isbeing sintered at high temperatures (e.g., above 500 degrees C.) withinsintering station 38B. Applicant has determined that the inducement of alongitudinal curve in the tape material via bending during sintering mayimprove cross-width shape of the final sintered tape 40B via themechanisms discussed herein.

In the specific embodiment shown in FIG. 58, bending system 1602Bincludes an upward facing convex curved surface 1604B that defines atleast a portion of the lower channel surface through sintering station38B. Upward facing convex curved surface 1604B defines at least oneradius of curvature, shown as R1B, and in specific embodiments, R1B isor includes a radius of curvature within the range of 0.01 m to 13,000m. In general, as unbound tape 36B is moved through sintering station38B, as discussed above, gravity and/or the pulling tension in the tapecauses tape to bend into at least partial conformity with curved surface1604B, inducing a longitudinal bend into the tape during sintering atelevated temperatures. In specific embodiments, the tension applied tounbound tape 36B is at least 0.1 gram-force per linear inch of width ofunbound tape 36B, and unbound tape 36B is moved at a speed of between 1inch and 100 inches of tape length per minute through sintering station38B.

As shown in FIG. 58, curved surface 1604B is curved around an axis thatis parallel to the width axis of unbound tape 36B (and is perpendicularto the plane of the view of FIG. 58). Thus, in such embodiments, unboundtape 36B follows a path through sintering station 38B generally definedby the channel 104B, and convex curved surface 1604B defines a curvedsection of the path through sintering station 38B. The bending isinduced in unbound tape 36B during sintering as it traverses the curvedsection of the path defined by convex curved surface 1604B by beingshaped into conformity with curved surface 1604B.

In the specific embodiment shown in FIG. 58, curved surface 1604B formsa continuous curved surface, having a single radius of curvature, thatextends the entire length of channel 104B, between the entrance andexit, of sintering station 38B. In such embodiments, the radius ofcurvature of surface 1604B needed to achieve both a sufficient level ofbending and to fully extend the length of sintering station 38B may varybased on the length of sintering station. As such, for a given maximumrise, H1B, (shown in FIG. 60) of curved surface 1604B, a short sinteringstation 38B may have a smaller R1B than a longer sintering station 38B.As a specific example, a sintering station 38B that is (at least) 1 mlong, may have a curved surface 1604B having an R1B between 1 m and 130m. As a specific example, a sintering station 38B that is (at least) 3 mlong, may have a curved surface 1604B having an R1B between 10 m and1130 m. As a specific example, a sintering station 38B that is (atleast) 6 m long, may have a curved surface 1604B having an R1 between 40m and 4500 m. As a specific example, a sintering station 38B that is (atleast) 10 m long, may have a curved surface 1604B having an R1B between120 m and 13,000 m. In such embodiments, regardless of length, H1B maybetween 1 mm and 10 cm resulting in the R1B ranges shown above.

As discussed above regarding system 10, sintering station 38B isarranged such that a plane intersecting the entrance and the exit of thesintering station forms an angle relative to a horizontal plane that isless than 10 degrees. As discussed above, this generally horizontalsintering arrangement allows unbound tape 36B to move through sinteringstation 38B in a generally horizontal position. In such embodiments,curved surface 1604B defines the lower surface of the path that tape 36Btraverses between the entrance and exit of sintering station 38B.Applicant believes that by combining the horizontal sinteringarrangement (discussed as reducing air flow-based thermal gradientsabove) with the formation of the longitudinal curved shape in the tapeduring sintering, sintered tape with the high levels of flatnessdiscussed herein can be produced and/or may be produced at rapid speeds,far faster than other sintering systems. It should be understood thatwhile Applicant believes that the bending during sintering incombination with the horizontal sintering station 38B provides highlevels of flatness, in other embodiments, sintering station 38B may bearranged at any angle from horizontal to vertical. In suchnon-horizontal embodiments, the dimensions and positioning of curvedsurface 1604B may be sufficient to achieve the desired level offlatness.

As shown in FIG. 58, in the processing arrangement of system 1600B, acontiguous length of tape material, such as unbound tape 36B, is movedinto a heating station, such as sintering station 38B. In thisarrangement, a portion of the contiguous tape, shown as unbound tape36B, is located upstream from the entrance 106B into sintering station38B. Following sintering, a sintered portion of the contiguous tape,such as sintered tape 40B, is located downstream from an exit 108B ofsintering station 38B. As will be generally understood, at any one givenpoint of time, the contiguous tape includes a third portion of tape thatis currently being sintered within sintering station 38B. This thirdportion of the contiguous tape is located between unbound, unsinteredtape 36B that is upstream from sintering station 38B and the sinteredportion 40B of the contiguous tape that is downstream from sinteringstation 38B. The portion of the contiguous tape currently beingsintered, shown as tape portion 1606B, is located within sinteringstation 38B as it is being heated to the desired sintering temperature(e.g., a temperature greater than 500 degrees C.).

In general, tape portion 1606B has a porosity that decreases or degreeof sintering that increases in the processing direction (e.g., fromright to left in the orientation of FIG. 58). As shown in FIG. 58, tapeportion 1606B is bent into conformity with upward facing, convex curvedsurface 1604B such that tape portion 1606B generally adopts a curvedshape having a radius of curvature matching R1B. As noted above, alongitudinally directed tension may be applied to the contiguous tapesuch that tape portion 1606B is bent into conformity with upward facing,convex curved surface 1604B.

As will generally be understood from the description of the unwind andtake-up portions of system 10 discussed above, system 1600B provides forcontinuous, reel-to-reel processing of a long contiguous length of tape.In this manner, the entire contiguous length of tape being processed maybe moved continuously and sequentially through sintering station 38Bsuch that the entire contiguous length of the tape being processedexperiences bending to the radius of curvature, R1B, of upward facing,convex curved surface 1604B during traversal of sintering station 38B.

Referring to FIG. 59, details of sintering station 38B including abending system 1602B are shown according to an exemplary embodiment. Inthe embodiment shown in FIG. 59, sintering station channel 104B isdefined, in part, by a tube 1608B (such as an alumina tube as discussedabove). In this embodiment, upward facing, convex curved surface 1604Bis defined by the upward facing surface of a furniture or insert 1610Bthat is placed within tube 1608B. As shown in FIG. 59, the length offurniture 1610B is at least 80%, specifically at least 90% and morespecifically at least 95% of the length of channel 104B. In someembodiments, the length of furniture 1610B is greater than the length ofchannel 104B such that incoming and exiting sections of the tape aresupported on the upward facing, convex curved surface 1604B as it entersand exits sintering station 38B.

As will generally be understood, in various embodiments, the radius ofcurvature that defines continuous convex curved surface 1604B is afunction of maximum rise, H1B, and the longitudinal length, L2B, ofsurface 1604 (e.g., the distance in the horizontal orientation of FIG.60). In specific embodiments, where convex curved surface 1604B extendsthe entire length of sintering station 38B, the longitudinal length ofsurface 1604B is substantially the same as the longitudinal length ofsintering station 38B. Thus, in such embodiments, the radius ofcurvature of convex curved surface 1604B, R1B, is defined asR1B=H1B+(L2B{circumflex over ( )}2)/H1B, and in various embodiments, 0.1mm<H1B<100 mm, and 0.1 m<L2B<100 m. In other contemplated embodiments,only portion of furniture 1610B forms a circular arc, and the surfacemay have another geometry having a radius of curvature (among a morecomplex geometry) or a maximum radius of curvature in ranges disclosedherein for R1B of furniture 1610B.

In specific embodiments, insert 1610B is removable from channel 104B andis removably coupled to or supported by tube 1608B. In such embodiments,this allows the different inserts 1610B having differently curvedsurfaces 1604B to be placed into sintering station 38B to provide aspecific bend radius needed to provide a desired level flattening for aparticular process or tape material type, thickness, rate of sintering,etc.

Referring to FIG. 60, in various embodiments, the lower surface ofchannel 104B through sintering station 38B is defined by upward facing,convex curved surface 1604B, and the upper surface of channel 104B isdefined by a downward facing, concave curved surface 1612B. In specificembodiments, a or the radius of curvature of downward facing, concavecurved surface 1612B generally matches (e.g., within 1%, within 10%,etc.) a or the radius of curvature of upward facing, convex curvedsurface 1604B, such as the corresponding radius of curvature verticallyaligned therewith. This curvature matchings ensures that the heightchannel 104B remains substantially constant along its length throughsintering station. In at least some designs, by having a constant heightand relatively low clearance relative to the tape being sintered,vertical movement of air within channel 104B due to thermal gradientscan be reduced, which is believed to improve shape and flatness of thefinal sintered tape.

In some embodiments, downward facing, concave curved surface 1612B is asurface of an insert 1614B. In such embodiments, insert 1614B isremovably coupled to or supported by tube 1608B which allows insert1614B to be selected to match the curvature of the lower furniture 1610Bas may be used for a particular process or material type.

Referring to FIG. 61, in various embodiments, the lower surface ofchannel 104B through sintering station 38B is defined by upward facing,convex curved surface 1604B that has more than one curved section, shownas curved sections 1620, 1622 and 1624. Put another way, curvature ofthe surface 1604B may include inflection points, discontinuities,non-circular-arcing, etc. As shown in FIG. 61 for example, curvedsection 1620B has a first radius of curvature, R1B′, curved section1622B has a second radius of curvature, R2B, and curved section 1624Bhas a third radius of curvature, R3B. In this embodiment, the path ofthe tape through sintering station 38B is defined by R1B′, R2B and R3B,and the tape during sintering is bent to each of radiuses R1B′, R2B andR3B sequentially while being heated within sintering station 38B. Invarious embodiments, R1B′, R2B and R3B are or include a radius ofcurvature between 0.01 m to 10 m. In specific embodiments, R1B′, R2Band/or R3B are different from each other.

Further, as shown in FIG. 61, in some embodiments, sintering station 38Bheats tape 36B traversing the different curved sections 1620B, 1622B and1624B to different temperatures. In one specific embodiment, thetemperature to which tape 36 is heated is inversely proportional toradius of curvature to which tape 36B is bent.

Referring to FIG. 62, in at least one embodiment, upward facing convexcurved surface 1604B is the upper surface of a gas bearing 1630B. Gasbearing 1630B includes a gas supply channel 1632B which deliverspressurized gas (e.g., air, nitrogen, helium, argon, etc.) to channel104B (see FIG. 60). In this manner, the pressurized gas supports tape36B during traversal of sintering station 38B which allows tape to bebent to the radius of curvature of surface 1604B without requiring orwith less contact with surface 1604B.

Referring to FIGS. 63 and 64, in various embodiments, bending system1602B includes one or more mandrel or roller, the outer surfaces ofwhich define a convex curved surface around which tape 36B is bentduring sintering within sintering station 38B.

The flattening provided by bending tape 36B around a curved structure,such as roller 1642B, is explained in more detail in relation to FIG.63. As shown in FIG. 63, a portion 1640B of tape 36B located upstreamfrom roller 1642B may have a buckle or flatness distortions shown ascross-width bow, represented by the curved dotted-line 1644B. Thisdefect may be caused by the complex bi-axial stresses created withintape 36B during sintering, as discussed above. As tape 36B is conveyedthrough sintering station 38B, it approaches roller 1642B with a radiusof curvature, ρ_(m). Tape 36B bends around roller 1642B and becomes flatin shape. Tape 36B may have a lesser stiffness in the flat configurationthan it does when it has the cross-width bow 1644B. The effect is a formof reverse-buckling or reduces changes of buckling. In the bent state,tape 36B with cross-width bow 1644B experiences a stress, σ_(d), on itssurface in the direction normal to that of conveyance that is directlyproportional to the curvature of cross-width bow 1644B, κ_(d), suchthat:

$\sigma_{d} = {\frac{1}{2}E\;\kappa_{d}t}$where t is the thickness of the tape and E is its elastic modulus. Thistechnique helps reduce other flatness distortions such as edge curl orbubble formation, with the result that local stress may be proportionateto the local curvature. Thus, bending, such as around roller 1642B oralong surface 1604B discussed above, aids in flattening across manydefect types. As will be explained in more detail below regarding FIG.65, flattening via bending does not require a surface against which thetape is pulled, and as such, flattening may also be achieved via bendingthrough a free-loop configuration.

However, utilizing a curved surface such as the outer surface of roller1642B or surface 1604B, discussed above, is advantageous in that itallows a tensile force to be applied externally to the tape, by devicessuch as a weighted dancer 1680B (FIG. 58). In such embodiments, theforce, F (FIG. 63), pulls the tape against the outer surface of roller1642B or surface 1604B and generates a second stress to aid inflattening the tape. The stress, σ_(F), from the applied tensile forceduring bending around a curved surface is defined by:

$\sigma_{F} = {\frac{2F}{wt}{\sin( \frac{\theta_{w}}{2} )}}$where w is the width of the tape and θ_(w) is the angle of contactbetween as the curved surface (whether the outer surface of roller 1642Bor surface 1604B) and tape 36B, often referred to as the wrap angle.

In various embodiments, roller 1642B can be fixed and unable to rotate.In other embodiments, roller 1642B may rotate freely. In yet otherembodiments, the rate of rotation of roller 1642B may be controlled tomatch the speed of conveyance of the tape or even to drive or retardconveyance. In various embodiments, roller 1642B may also be configuredto move up or down normal to the tape to change the wrap angle.

As shown in FIG. 64, in some embodiments, bending system 1602B mayinclude multiple rollers against which tape 36B is pulled duringsintering to provide flattening. In the specific embodiment shown inFIG. 64, bending system 1602B includes a pair of upper rollers 1650B anda single lower roller 1652B. As tape 36B is pulled through this rollerarrangement, tape 36B is bent in the longitudinal direction via contactwith the outer surfaces of rollers 1650B and 1652B. Similar arrangementsof gas bearings may be used, where one or more of the roller-to-tapeinterfaces shown in FIG. 64 correspond to outward blowing surfaces of arespective gas bearing, as shown in FIG. 62.

Referring to FIG. 65, in various embodiments, the curve or bend-formingpath that tape 36B traverses through sintering station 38B is formed viafree loop segment 1660B. In this embodiment, a section of tape 36B hangsunder the influence of gravity to generate the longitudinal bending asdiscussed herein. In such embodiments, bending system 1602B includes oneor more supports 1662B that are spaced apart from each other. Thespacing of supports 1662B defines a gap which allows tape 36B to hangdownward due to gravity between the supports to form free loop segment1660B having a radius of curvature, R1B″, as discussed above. In thisparticular embodiment, the radius of curvature R1B″ formed via thenon-contact, free-loop segment 1660B may improve surface quality infinal sintered tape 40B as compared to the various contact-based bendingsystems discussed herein. For example, utilizing free loop segment 1660Beliminates or reduces scratches that may form in contact-based systems.As another example, utilizing free loop segment 1660B eliminates orreduces diffusion of chemical constituents from surfaces which thesintering tape may come in contact with in contact-based systems.

Applicant has performed tests that demonstrate that longitudinal bendingwhile sintering of various contiguous tape materials decreases flatnessdistortions. Some results from these tests are illustrated in FIG. 66.For example, as shown in FIG. 66, 40 μm thick tapes of 3 mole percentyttria-doped zirconia (left) and titanium oxide (right) were bent duringsintering. The tapes were cast onto a flat surface and were reformed toa curved shape over the alumina rod. More specifically the tapes weredraped across a 9.5 mm diameter alumina rod and then heated at 100°C./hr to 1150° C. The dwell time was five minutes. The regions of tapebent across the alumina rod are locally flat from one edge to the next(in the width direction). In contrast, regions of the tape not supportedby the curved surface of the rod were free to respond to shrinkagemismatches and forming flatness distortions. Specifically, wrinkles inthe zirconia tape are visible and emphasized with dotted black lines.The images also evidence the plasticity of the tapes, where stressesover the rod induce flattening.

Referring now to FIGS. 67A and 67B, an example of products describedabove is shown. More specifically, a roll of polycrystalline ceramictape includes alumina with 1% by volume yttria-stabilized zirconia withconstituents ZrO₂ and 3 mol % Y₂O₃. The polycrystalline ceramic tape is70 micrometers thick, 36 millimeters wide, and over 8.5 m long. Thistape was sintered with the above-described processes using theabove-described equipment at a sintering temperature of 1650° C. and ata rate of about 10 cm per minute along the manufacturing line. The rollhas a 3 to 6 inch diameter core. The tape is flat or flattenable asdiscussed above.

FIG. 68 shows an example of a roll of polycrystalline ceramic tape thatis alumina with 300 parts per million magnesium oxide. The tape in FIG.68 is 77 microns thick, 36 mm wide, and longer than 8 m. This tape wassintered with the above-described processes using the above-describedequipment at a sintering temperature of 1650° C. and at a rate of about10 cm per minute along the manufacturing line. The roll has a 3 to 6inch diameter core. The tape is flat or flattenable as discussed above.

FIG. 69 shows an example of a roll of polycrystalline ceramic tape thatis yttria-stabilized zirconia (ZrO₂ with 3 mol % Y₂O₃). The tape in FIG.69 is 33 mm wide and about a meter long. This tape was sintered with theabove-described processes using the above-described equipment at asintering temperature of 1575° C. and at a rate of about 15 to 23 cm perminute along the manufacturing line. The roll has a 3 to 6 inch diametercore. The tape is flat or flattenable as discussed above.

Accordingly, aspects of the present disclosure, as discussed above,relate to a roll of flat or flattenable polycrystalline ceramic orsynthetic mineral tape of materials disclosed or described herein, suchas alumina tape as in FIGS. 67A and 67B, that is at least partiallysintered such that grains of the polycrystalline ceramic or syntheticmineral are fused to one another, the polycrystalline ceramic orsynthetic mineral tape comprising a thickness of no more than 500micrometers, a width at least 10 times greater than the thickness, and alength such that the width is less than 1/10th the length, wherein thelength of the polycrystalline ceramic or synthetic mineral tape is atleast 1 meter. In some such embodiments, the width of thepolycrystalline ceramic or synthetic mineral is at least 5 millimeters,and the width of the polycrystalline ceramic or synthetic mineral tapeis less than 1/20th the length of the polycrystalline ceramic orsynthetic mineral tape, such as where the thickness of thepolycrystalline ceramic or synthetic mineral tape is at least 10micrometers and/or where the thickness of the polycrystalline ceramic orsynthetic mineral tape is no greater than 250 micrometers, such as wherethe thickness of the polycrystalline ceramic or synthetic mineral tapeis no greater than 100 micrometers and/or where the thickness of thepolycrystalline ceramic or synthetic mineral tape is no greater than 50micrometers. In some such embodiments, the polycrystalline ceramic orsynthetic mineral tape has fewer than 10 pin holes of a cross-sectionalarea of at least a square micrometer passing through the polycrystallineceramic or synthetic mineral tape, per square millimeter of surface onaverage over a full surface of the polycrystalline ceramic or syntheticmineral tape. In some such embodiments, the polycrystalline ceramic orsynthetic mineral tape has fewer than 1 pin hole of a cross-sectionalarea of at least a square micrometer passing through the polycrystallineceramic or synthetic mineral tape, per square millimeter of surface onaverage over a full surface of the polycrystalline ceramic or syntheticmineral tape. In some such embodiments, the length of thepolycrystalline ceramic or synthetic mineral tape is at least 10 meters,the width of the polycrystalline ceramic or synthetic mineral tape is atleast 10 millimeters, such as where the width of the polycrystallineceramic or synthetic mineral tape is no greater than 20 centimetersand/or where the polycrystalline ceramic or synthetic mineral tape hashigh surface quality such that first and second surfaces of thepolycrystalline ceramic or synthetic mineral tape both have at least asquare centimeter of area having fewer than ten surface defects fromadhesion or abrasion with a dimension greater than five micrometers, thehigh surface quality facilitating strength of the sintered article. Insome such embodiments, the polycrystalline ceramic or synthetic mineraltape supports greater than 1 kilogram of weight without failure, and/orthe polycrystalline ceramic or synthetic mineral tape supports about 20megapascals of tension without failure, such as where the width of thepolycrystalline ceramic or synthetic mineral tape is at least 50millimeters. In some such embodiments, the polycrystalline ceramic orsynthetic mineral tape has total transmittance of at least 30% atwavelengths from about 300 nm to about 800 nm and/or the polycrystallineceramic or synthetic mineral tape has diffuse transmission through thepolycrystalline ceramic or synthetic mineral tape of at least about 10%up to about 60% at wavelengths from about 300 nm to about 800 nm, and/orthe polycrystalline ceramic or synthetic mineral tape is translucentsuch that text in contact with the polycrystalline ceramic or syntheticmineral tape may be read through the polycrystalline ceramic orsynthetic mineral tape. In some embodiments the roll is furthercomprising a mandrel or spool, where the polycrystalline ceramic orsynthetic mineral tape bends around the mandrel or spool at a diameterof 1 meter or less such as where the polycrystalline ceramic orsynthetic mineral tape is wound on the spool, such as where the spoolhas a diameter of at least 0.5 centimeters and no greater than 1 meter.In some such embodiments, the polycrystalline ceramic or syntheticmineral tape is fully sintered and dense, having a porosity of less than1%, such as where the polycrystalline ceramic or synthetic mineral tapehas a porosity of less than 0.5%. In some such embodiments, thepolycrystalline ceramic or synthetic mineral tape is substantiallyunpolished such that surfaces of the polycrystalline ceramic orsynthetic mineral tape have a granular profile, such as where thegranular profile includes grains with a height in a range fromtwenty-five nanometers to one-hundred-and-fifty micrometers relative torecessed portions of the surfaces at boundaries between the respectivegrains and/or the granular profile includes grains with a height in arange from twenty-five nanometers to one-hundred micrometers relative torecessed portions of the surfaces at boundaries between the respectivegrains and/or the granular profile includes grains with a height of atleast fifty nanometers relative to recessed portions of the surfaces atboundaries between the respective grains and/or the granular profileincludes grains with a height of no more than eighty micrometersrelative to recessed portions of the surfaces at boundaries between therespective grains. In some such embodiments, while being substantiallyunpolished, at least one surface of the In some such embodiments, thetape has a roughness in a range of one nanometer to ten micrometers overa distance of one centimeter in a lengthwise direction along thesurface.

According to an exemplary embodiment, an article (e.g., tape of sinteredceramic, as disclosed herein), has a thickness of less than 50micrometer or other thicknesses as disclosed herein, and fewer than 10pin holes (i.e., passage or opening through body from first to secondmajor surface having a cross-sectional area of at least a squaremicrometer and/or no larger than a square millimeter), per squaremillimeter of surface on average over the full surface (or fewer than 10pin holes over the full surface, if the surface area is less than asquare millimeter; or alternatively on average over a long length of thearticle, such as over 1 meter, over 5 meters), such as fewer than 5 pinholes, fewer than 2 pin holes, and even fewer than fewer than 1 pin holeper square millimeter of surface on average over the full surface orlong length. Pin holes are distinguished from vias, which are purposelycut, typically in pattern of a repeating geometry (e.g., circular,rectilinear) to be filled with conductive material for example, orperforations formed in a pattern of a repeating geometry, which may helpas fiducial marks with alignment in roll-to-roll processing for example.

FIG. 70 compares sintering schedules for sintering of ceramics (e.g.,alumina) using the processes disclosed herein, compared to traditionalbatch firing in a kiln using setters, and stacked green ceramic plates.The total time for processing at sintering temperatures, includingmultiple passes (e.g., 2, 3, 4 passes) through the furnace systemdisclosed above, may be less than one hour. Conventional sintering maytake 20 hours. Applicants have discovered measurable, identifiabledifferences between the “fast” sintering of the present disclosureversus traditional, such as with respect to the microstructure ofceramics manufactured according to the present technology. Morespecifically, Applicants have found that fast firing of thin, unstackedtapes, as disclosed above, results in less melding or combining ofindividual particles or grains into one another. The resulting sinteredgrain size of the present technology is substantially smaller and closerto the original green state grain size or particle size. Whereastraditional sintering may result in sintered grains that are ten timesthe original particle sizes, grains of polycrystalline ceramicsmanufactured with the fast sintering schedule disclosed herein may havesintered grain sizes that are less than five times the original greenstate grain or particle sizes, such as less than three times on average.Furthermore, and surprisingly, articles manufactured according to thepresent technology also may have correspondingly high density, such asat least 90% relative density, at least 95% relative density, at least98% relative density, and this high relative density is achieved withthe relatively small grain size, as just described, which may be lessthan 10 micrometers mean particle size, such as less than 5 micrometers,such as less than 3 micrometers, depending upon the starting particlessizes and composition, such as for alumina, cubic zirconia, ferrites,barium titanate, magnesium titanate, and other inorganic materials thatmay be processed into tapes, sheets, etc. using the technology asdisclosed herein.

Some embodiments may use multiple passes through a furnace for sinteringthe same article (e.g., tape), such as a first pass (“bisque pass”) toincrease strength of the tape after organic binder is removed, as secondpass to partially sinter the tape, a third pass to further sinter thetape, and a forth pass to sinter to final density. Use of multiplepasses or a series of furnaces or hot zones may help to control stressesin the tape due to shrinkage of the tape material during sintering. Forexample, some furnaces for sintering may be 12 to 14 inches long, whileothers may be 40 to 45 inches long, others over 60 inches, and stillothers of other lengths. For shorter furnaces, multiple passes orarrangements of multiple furnaces in series may be particularly helpfulfor sintering inorganic materials with greater degrees of shrinkage.Also, longer furnaces or arrangements of furnaces in series may alsoallow for faster rates of green tape movement, by increasing soak times(i.e. exposure to sintering conditions) at such faster rates.

After analyzing samples sintered at a high speed (e.g., rate of 4 inchesper minute) with a sintering temperature (e.g., 1650° C.), that areparticularly thin, as described herein (e.g., a thickness of 20 to 77micrometers), alumina or other materials disclosed herein made with thepresently disclosed technology may have the following attributes:material purity of at least 90% by volume, such as at least 95%, such asat least 99%, where high purity may result from the narrow passage andcontrol of air flow as well as the time of sintering, efficiency of thebinder removal, and starting constituents, among other factors describedherein; surface roughness measured by AFM in units of nanometers of lessthan 100, such as less than 60, such as about 40 for shiny face and/orless than 150, such as less than 100, such as about 60 for mat face,when measured at a 30 mm scan, where the mat face is rougher than theshiny face due to interface with a floor of the sintering furnace; grainsize of about 1 mm in cross-section, or other grain sizes as disclosedherein; porosity of less than 10% by volume for a sintered article, suchas less than 5%, such as less than 3%, such as less than 1%, such asless than even 0.5%, which may in part be due to the fast firingprocess, which maintains small grain/particles sizes as disclosed above,whereby gas may be less likely to be trapped within grains, as may be acharacteristic limitation for traditional batch sintering and longerfiring processes (limiting phenomenon known as ‘pore/boundaryseparation’ which may be overcome by sintering processes as disclosedherein). Alumina tape manufactured according to technology disclosedherein has a specific heat capacity of at least and/or no more thanabout 0.8 J/gK at 20° C. and 1.0 J/gK at 100° C. as measured via ASTME1269 standard test protocol/method; hardness at room temperature (23°C.) measured via nano-indentation of at least and/or no more than about23.5 GPa, such as on at least and/or no more than about a 40 μm thickalumina tape, and/or other tape or sheet sizes disclosed herein;two-point bending strength of at least and/or no more than about 630MPa, such as at least in part due to control of voids and smaller grainsize; elastic modulus of at least and/or no more than about 394 GPa asmeasured via dynamic mechanical analysis (DMA) for 3 point bend;coefficient of thermal expansion of at least and/or no more than about6.7 ppm/° C. average over the range of 25-300° C., at least and/or nomore than about 7.6 ppm/° C. average over the range of 25-600° C., atleast and/or no more than about 8.0 ppm/° C. average over the range of25-300° C.; dielectric strength of at least about 124.4 kV/mm at 25° C.as per ASTM D149 standard test protocol/method, such as on at leastand/or no more than about a 40 μm thick alumina tape; dielectricconstant (Dk) of at least and/or no more than about 9.4 at 5 GHz and ofat least and/or no more than about 9.3 at 10 GHz as per ASTM D2520standard test protocol/method; dielectric loss/loss tangent of at leastand/or no more than about 8×10⁻⁵ at 5 GHz and of at least and/or no morethan about 1×10⁻⁴ at 10 GHz as per ASTM standard test protocol/method(D2520); volume resistivity of at least and/or no more than about 3×10¹⁵ohm-centimeter at 25 as per D257, at least and/or no more than about4×10¹⁴ ohm-centimeter at 300 as per D1829, and/or at least and/or nomore than about 1×10¹³ ohm-centimeter at 500 as per D1829; transmittanceof at least about 50%, such as at least about 60%, such as at leastabout 70% for one, most, and/or all wavelengths between about 400-700nanometers, such as on at least and/or no more than about a 40 μm thickalumina tape, and/or other tape or sheet sizes disclosed herein;transmittance of at least about 50%, such as at least about 65%, such asat least about 80% for one, most, and/or all wavelengths between about2-7 micrometers and/or between about 2-7 millimeters, such as on atleast and/or no more than about a 40 μm thick alumina tape, and/or othertape or sheet sizes disclosed herein; and less than 100 ppm outgassingas measured via GC-MS at 200° C., such as less than 50 ppm, such as lessthan 10 ppm.

Referring now to FIGS. 71A and 71B, two samples of alumina as shownside-by-side to demonstrate impact of sintering time and temperature.The alumina of FIG. 71A was processed through above disclosedmanufacturing system at a rate of 4 inches per minute, having a 4 minutehot “soak” or exposure to 1650° C. sintering temperature, while thealumina of FIG. 71B was manufactured at 8 inches per minute, having a 2minute soak at 1600° C. As can be seen, the grain size greatly increasesas sintering time increases, however porosity is low in both figures,such as below 5% by volume. FIGS. 72A and 72B show cross-sectionaldigital images of ceramic tape made via corresponding processes: FIG.72A at 8 inches per minute at 1650° C. and FIG. 72B at 4 inches perminute at 1600° C.

FIGS. 73A, 73B, and 73C show increasing magnification of grainboundaries of alumina manufacturing according to the present technology.Of interest is that the grain boundaries of articles manufacturedaccording to the present technology are particularly pristine. As shownin FIG. 73C, the molecular arrays of the adjoining crystal grains(crystal lattices) essentially directly contact one another, such thatthere is less than 5 nm of intermediate amorphous material, such as lessthan 3 nm of intermediate amorphous material, such as less than 1 nm ofintermediate amorphous material. Applicants believe that the crystalgrain interface may be, at least in part, attributed to the fastsintering, gas flow control, and binder burn-off technology disclosedherein. FIGS. 74 and 75 show other grain boundaries of articles ofpolycrystalline ceramic or synthetic mineral according to the presenttechnology. Applicants believe hermeticity and/or strength of sucharticles may be particularly advantageous relative to ceramics havingsome or more amorphous material between grains. The images of FIGS.73-75 were gathered via transmission electron microscope.

FIGS. 76 and 77 show similar microstructure for different materials.FIG. 76 corresponds to alumina with 1% by volume yttria-stabilizedzirconia (ZrO₂ with 3 mol % Y₂O₃) processed at 4 inches per minute andat 1650° C. Similarly, FIG. 77 shows a polished cross-section of aluminawith 1% by volume titanium oxide (TiO₂) processed at 4 inches per minuteand at 1550° C.

FIG. 78 is a digital image of a ribbon of high purity fused silicamanufactured from loose silica particles bound in green tape asdisclosed herein. The silica particles are inorganic, but may not becrystalline or a synthetic mineral. Accordingly, Applicants have foundthat the technology disclosed herein may be used to manufacture tapes,with geometries as disclosed herein for polycrystalline ceramic andsynthetic mineral, but comprising, consisting essentially of, orconsisting of inorganic material that may be amorphous, such as glassthat is difficult to manufacture via float or fusion forming processes,such as silica or other glasses having a high melting temperature and/orhigh viscosity, such as a glass transition temperature of at least 1000°C.

FIGS. 79A and 79B show the polished cross-section of sintered tape ofsilica having a granular profile. The tape of 79A and 79B wasmanufactured at a sintering temperature of 1150° C. Individual particleso silica have been fused together to form the tape. As shown in FIG.79B, the particles are generally spherical and have a cross-section ofless than a micrometer. By contrast, FIG. 80 shows silica tapemanufactured according to the technology disclosed herein, as sinteredat 1250° C. The granular profile is still present, but is muted relativeto the silica of FIG. 79B. FIG. 81 shows fully dense and amorphoussilica that has been sintered according to the present disclosure at1300° C. Applicants contemplate that silica tape with a granular profilemay be useful for scattering of light or other applications.Accordingly, FIGS. 79 to 81 demonstrate that compositions disclosedherein may be in the form of an amorphous article, such as a tape, ifprocessed at a high enough temperature. With that said, Applicants havefound that if the tape is heated too much, the tape may become difficultto handle and/or may lose shape.

Referring now to FIG. 82, rapid thermal processing and continuoussintering, such as of inorganic tape, may be used to producelithium-containing materials, as discussed above, such as for use as athin cathode structure in lithium batteries. For example, Applicantsbelieve lithium-containing materials, such as lithium manganate spinel(LiMn₂O₄), LiCoO₂ or LiFePO₄, are good candidates cathode structure.Unexpectedly, Applicants have found that the presently disclosedtechnology mitigates lithium loss due to high vapor pressure and/ormitigates change in reduction in valence of the transition metal oxideand release of oxygen on heating. For example, FIG. 82 shows powderx-ray diffraction traces for similar 30 μm thick tapes containingLiMn₂O₄ powder (commercially available from Novarials, Sigma Aldrich,Gelon, Mtixtl, and/or others) that was rapidly sintered at 1250° C. for6 minutes using the presently disclosed technology and LiMn₂O₄ powderconventionally sintered at 1250° C. for 4 hours. As shown in FIG. 82,the rapidly sintered material is still single phase spinel with peakintensities and positions of LiMn₂O₄. The lithium is retained and so isthe average valence of 3.5 for the manganese ions. Accordingly, suchlithium-containing articles (e.g., tapes, sheets) sintered by thepresently disclosed technology may meet minimum chemical and phaserequirements for a cathode supported battery. In contrast, theconventionally sintered tape is mostly Mn₃O₄ with lesser amount ofLiMn₂O₄ remaining, as shown in FIG. 82. There was extensive loss oflithium and a drop in average manganese valence to 2.67.

Applicants have also found that the presently disclosed sintering systemmay be advantageous for pore removal during sintering, such as whenrapidly sintering lithium-containing inorganic materials, such asLiMn₂O₄, and/or other materials susceptible to vaporization of volatileconstituents. With conventional sintering techniques, grain growth maylimit pore removal, such as by trapping pores within larger grains.

For comparison purposes, Applicants manufactured a pill of die-formedLiMn₂O₄ sintered at 1300° C. The mean particle diameter of the powderused to make the pill was 0.5 μm; to enhance surface tension and favorpore removal. Loss of lithium and change of Mn-valence were controlledor slowed in three ways. First, the size of the pill was large, greaterthan 25 mm in diameter and 5 mm in thickness to provide surplusmaterial. Second, the sintering was performed under a cover. Third, thepill was supported on platinum. Powder x-ray diffraction confirmed theresulting pill is single phase lithium manganite spinel and chemicalanalysis shows negligible lithium loss relative to the as-receivedmaterial and that the average valence of Mn is 3.5. The average grainsize of the sintered pill is about 40 μm and there is more than 15% ofporosity.

Returning to the presently disclosed technology, porosity in sinteredmaterials may be limited or particularly low, and grains may beparticularly small, which may be beneficial in applications, such ascathode support. By contrast, excess porosity and large grains may bedetrimental to strength of most ceramics. Further, Applicants have foundthat rapid thermal sintering, using techniques and equipment disclosedherein, favors pore removal over grain growth. Referring to FIGS. 83 and84, as-fired surfaces of rapidly sintered LiMn₂O₄ tape (FIG. 83,sintered at 1250° C. for 6 min; and FIG. 84 sintered at 1350° C. for 3min). The initial mean particle diameter was 0.5 μm, like the above pillexample. The amount of porosity is much lower than in the example of theconventionally sintered pill. More specifically, the porosity appearsclosed and in an amount less than 5%. The grains are also smaller thanthe above pill example. More specifically, the grains are about 10 μmand 25 μm, respectively in FIGS. 83 and 84. Put another way, porosity oflithium-containing sintered material (e.g., lithium manganite) was lessthan 15%, such as less than 10%, such as less than 7%, such as less thanabout 5% and/or the grains were less than 40 μm, such as less than 30μm. Also different than conventional sintering of lithium-containingmaterials, the present technology uses thin sheets or tapes as disclosedherein, as opposed to large volume pills or boules, which facilitatesthe rapid sintering; controlling loss of volatile constituents byreducing the time of sintering, with or without control of surroundingvapor pressures. Applicants contemplate that the presently disclosedsintering system, including the rapid thermal sintering, may alsofacilitate sintering at an even lower temperature and/or sintering on analumina or other low-cost support in a continuous process as disclosedherein.

LiCO₂ and LiFePO₄ are other examples of lithium-containing inorganicmaterials that may be sintered using the presently disclosed technology,and may be useful as cathode material or for other applications. Moregenerally, sintering of other transition metal oxides with minimal lossof oxygen is possible is possible using the presently disclosedtechnology.

Referring now to FIGS. 85A and 85B, the cross-section of a green tape isshown under two different levels of magnification. More specifically, aslip for the green tape was made of about 47.35 wt % of a garnet powderwith the composition Li_(6.5)La₃Zr_(1.5)Ta_(0.5)O₁₂, 6.45 wt % lithiumcarbonate, 31.74 wt % n-propyl propionate, 1.30 wt % glyceryl Trioleate,3.56 wt % n-butyl stearate, and 9.60 wt % Lucite International Elvacite2046, a high molecular weight iso-butyl/n-butyl methacrylate co-polymer.The slip mixture was vibratory milled for 18 hours. The slip was cast ona Teflon carrier film with a 10 mil blade and dried overnight. Theresulting dried tape was about 85 to 90 μm thick with particlesaveraging 0.6 μm. The green tape has been released from the carrier filmin FIGS. 85A and 85B.

In this example, the binder was subsequently burned off of the greentape of FIGS. 85A and 85B at 400° C., where environment for the burn-offwas controlled to be argon gas and time for the binder burn-off was 30minutes. Next the tape with burned-out/charred binder was fired in acontinuous sintering furnace as disclosed herein at 1200° C. for 15minutes in air. The fired tape was at least and/or no more than about 50to 55 μm thick with grain sizes averaging at least and/or no more thanabout 2 to 3 μm, as shown in FIGS. 86A and 86B. The resulting tape hadconductivities at least and/or no more than about 3.7×10⁻⁴ to 3.8×10⁻⁴S/cm, where S is siemens. The fired samples were at least and/or no morethan about 96 to 98 wt % cubic garnet phase.

Using the presently disclosed technology, some embodiments include useof high-lithium content for forming particularly dense garnet tape orother articles. Applicants have found that excess lithium (excess interms of more than the lithium according to stoichiometry of thesintered article, such as at least 1 vol % excess, at least 10 vol %excess, at least 20 vol % excess, at least 50% vol %, and/or no morethan 100 vol % more than the stoichiometric amount in the sinteredarticle) in the green tape may promote dense garnet tape sinteringand/or compensate for loss of lithium during the sintering. Suchhigh-lithium content powder for use in the green tape may be made bybatching with excess amounts of lithium precursor in the raw material ingarnet powder preparation and/or by making stoichiometric or slightlyexcess (no more than 50 vol % excess relative to final articlestoichiometry) lithium garnet powder and then adding in more lithiumprecursor during slip preparation for tape casting. Some advantages ofthe latter approach include that the lower lithium-containing batch maybe easier to prepare because high lithium content may be hygroscopic anddifficult to mill and/or the amount of excess lithium may be easilyadjusted to compensate for different processing conditions. Examples oflithium precursors for adding such excess lithium during the slippreparation include Li₂CO₃, LiOH, LiNO₃, LiCl, etc. Methods of addingexcess lithium as just described include having lithium precursorpre-react with the garnet powder, such as by heating the lithiumprecursor and garnet powder mixture to about 900 to 950° C. for about 1to 5 hours. Alternatively, without pre-reaction, the excess lithium maybe added as a fine precursor powder and/or by providing enough millingto decrease the particle size to prevent leaving pores in the ceramic,such as precursor powder particle size of less than 3 micrometers, suchas less than 1 micrometer. Applicants have found that the amount ofexcess lithium is enough for sintering via the above-describedtechnology, but not too much so as to leave excess lithium in thesintered article or to cause tetragonal phase formation. Accordingly, atleast and/or no more than about 5.8 to 9 mol total lithium per mol ofgarnet, for garnet that sinters at at least and/or no more than about1000° C. in at least and/or no more than about 3 minutes (e.g., lowlithium-content garnet); at least and/or no more than about 7 to 9 moltotal lithium per mol of garnet, for garnet that sinters at at leastand/or no more than about 1150° C. in at least and/or no more than about3 minutes. With that said, for garnet, especially high lithium-contentgarnet, that may be highly reactive to organics used in tape castingslip, to stabilize the garnet, the powder may be treated beforehandusing an acid treatment, such as peracetic acid (peroxyacetic acid,PAA), citric acid, stearic acid, hydrochloric acid, acetic acid; asolvent, such as a non-water containing solvent, such as isopropylalcohol, PA, PP, etc.; with a treatment of soaking the garnet powder,which may be excess lithium precursor pre-reacted garnet powder asdisclosed above, in 1 to 5 wt % acid/solvent solution for 2 hours, withsolid loading of about 50%, then drying the solvent, where theobtained/treated powder may be used for making tape casting slip.Alternatively, low lithium-content garnet powder plus inert lithiumprecursor, such as Li₂CO₃, may be used in making a casting slipdirectly.

At least one embodiment of acid treatment includes ball milling for 3hours and oven drying at 60° C. 100 grams of MAA(Li_(5.39)La₃Zr_(1.7)W_(0.3)Ga_(0.5)O_(x), lithium garnet or cubic LLZO(e.g., Li₇La₃Zr₂O₁₂), low lithium-content garnet powder) plus 10.7 gramsLi₂CO₃, 2.2 grams of citric acid, and 100 grams of isopropyl alcohol. Atleast one embodiment of tape casting slip manufacturing includesattrition milling for 2 hours 100 grams of acid treated MAA plus 10.7 wt% Li₂CO₃, 84.67 grams methoxy propyl acetate solvent, 12.14 grams PVBButvar B-79 binder, and 2.4 grams dibutyl phthalate plasticizer. Anotherembodiment of tape casting slip manufacturing includes attrition millingfor 2 hours 100 grams of acid treated MAA plus 8.4 wt % Li₂CO₃ that hasbeen pre-reacted in turbular mix for 30 minutes and calcine at 900° C.for 1 hour, 66.67 grams ethanol and 33.33 grams butanol solvent, 12grams PVB Butvar B-79 binder, and 10 grams dibutyl phthalateplasticizer. Another embodiment of tape casting slip manufacturingincludes 100 grams of GP (Li_(6.1)La₃Zr₂Al_(0.3)O₁₂, lithium garnet orcubic LLZO) plus 8.4 wt % Li₂CO₃ that has been pre-reacted (e.g., mixedfor 30 minutes and heated to 900° C. for 1 hour), 66.67 grams ethanoland 33.33 grams butanol solvent, 12 grams PVB Butvar B-79 binder, and 10grams dibutyl phthalate plasticizer. Applicants have found that lowlithium content garnet with Li₂CO₃ for excess lithium precursor, asdescribed above, may not require acid treatment; for example, attritionmilling for 2 hours 100 grams of MAA with 10.7% Li₂CO₃, 84.67 gramsmethoxy propyl acetate solvent, 2.08 grams fish oil (Z1) dispersant,12.14 grams of PVB Butvar B-79 binder, and 2.4 grams of dibutylphthalate plasticizer. Alternatively, acid based dispersant may be addedinto the slip, such as with up-milling for two hours 100 grams MAA with10.7% Li₂CO₃, 104 grams EtOH and BuOH in a 2:1 ratio solvent, 1 gram ofcitric acid as dispersant, 16 grams PVB B-79 as binder, and 14 grams ofdibutyl phthalate as plasticizer.

Aspects of the present technology relate to sintering of higherviscosity, higher processing temperature glasses, such as fused silicaor ultra-low-expansion (amorphous) glass compositions that may bedifficult or impossible to manufacture as rolls of high viscosity glasstape and/or cut into sheets via other methods, such as fusion drawing,float glass, or other ordinary glass tank melters. Accordingly,inorganic material with geometries (e.g., thicknesses, rolled format,lengths, widths) and attributes (e.g., flatness, low warpage) disclosedherein include higher viscosity, higher processing temperature glassesmanufactured with the present technology. Additional benefits of thepresent technology include compositional homogeneity at small(sub-millimeter) length scale and large length scale (millimeter tomulti-centimeter variations) via use of controlled air flow duringsintering, tension control of the tape, and mixed powders in a slurry asopposed to flame deposition techniques, which may lead to compositionalvariations at different scales. Additionally, the rolls or sheets ofhigher viscosity, higher processing temperature glasses may be annealed.Applicants have found that the presently disclosed technology, includingfurnace with heat zones, not only allows sintering but also an abilityto continuously anneal the glass tape as it is being formed and/or via aset of one or more lower temperature furnaces. A corresponding low anduniform stress field in annealed glass facilitates uniform dimensionalchanges during post-firing leading to less warpage in thin, post-treatedannealed sheets compared to unannealed articles. Further, technologydisclosed herein, including lower temperature processing (compared toflame deposition with temperatures typically greater than 2100° C.) andrapid sintering (compared to batch sintering), also facilitatesincorporation of volatile dopants such as boron and phosphorous atlevels greater than 0.5 wt % of such inorganic material (e.g., viscous,high temperature amorphous glasses), which may be difficult orimpossible to add via flame deposited materials. With that said,equipment disclosed herein may be used to heat green or partiallysintered materials to a higher temperature than would typically be usedin a conventional sintering process, where the short time at soak limitsgrain growth and accelerates pore removal.

Applicants have found a high level of compositional homogeneity withviscous, high temperature amorphous glass articles, when green tape ismade with glass powder mixed in slurry form, such as in the solgel,extrusion, or casting processes and sintering is performed as describedabove. More specifically, Applicants have found hydroxide (OH),deuterium (OD), chlorine (Cl) and fluorine (F) variations less than+/−2.5 ppm at spatial variations of 1 mm and less than +/−5 ppm withindistances 3 cm, such as with variations less than +/−1 ppm atfrequencies less than 1 mm and less than +/−3 ppm at frequencies lessthan 3 cm. In some embodiments, compositional homogeneity is withchemical variations of titania of less than +/−0.2 wt %, such as lessthan +/−0.1 wt % at distances of 1 mm in titania containing glass, andless than 10 wt % at distances of 1 mm variations in Germania levels inGermania containing glass. In some embodiments, index variations lessthan 10 ppm, such as less than 5 ppm as measured via XRF techniques (wt% metals) when mixed component glasses are used.

Referring now to FIG. 87, examples of viscous, high temperatureamorphous glasses made with the present technology are shown in solidlines, and those made with conventional techniques are shown with adotted line (soda lime glass (SLG) and a mixed barium borosilicateglass) where viscosities are low and the glasses may be processed byconventional glass methods such as the float glass process where manysoda lime glasses are produced such as ordinary window glasses. FIG. 1also identifies the viscosity behavior of many high temperature glasses(solid lines), such as silica with 7.5 wt % titania, fused silica,silica with about 60 parts per million OH, silica with about 14 wt %GeO₂, silica with about 1 ppm OH, silica with about 150 ppm Cl, silicawith 3.1 wt % B₂O₃ and 10.7 wt % TiO₂. Characteristics for glasses thatmay be uniquely processed with technology disclosed herein are: annealpoints (viscosities of 1013 poise) greater than 800° C. and/or a silica(SiO₂) content of greater than 85 wt %, such as with greater than 95 vol% amorphous or less than 5 vol % crystals present, such as no crystalspresent (amorphous). Such glass may be in the form of rolls of hightemperature annealed glass. For some such embodiments, glass thicknessesless than about 400 μm (e.g., less than 200 μm) facilitate the glass tobe rollable in diameters less than a few meters, such as less than 1meter, such as less than 0.5 meters.

Applicants have found that cooling rate differences resulting from airflow differences, turbulence in air flow, as well as radiative coolingor heating differences from surrounding furnace environments orfixturing may produce localized stress differences in the glass as theglass cools to temperatures below the anneal point, which are lockedinto the glass. Compositional variations may also impact glassviscosity, and these compositional differences may result in differentstresses, fictive temperatures, index of refractions, thermalexpansions. If the glass is next re-heated to temperatures where thefree standing glass could deform, then unconstrained glass warpage mayoccur. Such reheating may be needed in downstream processing, such asfor thin film deposition for example and warping may be undesirable.However, Applicants have found that annealing glasses manufactured viaprocesses disclosed herein, such as by controlled cooling in amulti-zone furnace, or by passage through an annealing furnacesubsequent to sintering (opposite the binder burnout system), helpsmitigate differences in tension across the article (e.g., sheet) widthas the glass is being rolled and/or helps mitigate instances ofdifferent stress levels remaining trapped in the glass. Low and uniformstress levels are identified in glass taken from the roll and left freestanding. More specifically, absolute stress levels less than 10 MPawith variations across the article (e.g., sheet or tape) less than +/−5MPa are identified when the tape is freely resting on a flat surface,such as with absolute stress levels less than 5 MPa with variations lessthan +/−2 MPa, such as with absolute stress fields less than 2 MPa withvariations less than +/−1 MPa. Some embodiments of the presentdisclosure include glass, as described, having a relatively uniformstructure in terms of fictive temperature, such as variations less than+/−20° C., such as less than +/−10° C., such as less than +/−5° C. asmeasured by FTIR across a width of the respective article. Uniformstructure in terms of fictive temperature, may influence properties ofthe glass, such as optical or thermal expansion of the glass, such aswhere better expansivity may be obtained via uniform lower fictivetemperature, for example.

As indicated above, the present technology may be uniquely suited toprocess thin ribbons or sheets of viscous, high temperature amorphousglasses. Such glasses may have a viscosity of 12.5 poise only attemperatures exceeding 900° C., where at lower temperatures theviscosity is higher than 12.5; such as a viscosity of 13 poise only attemperatures exceeding 900° C., such as only at temperatures exceeding1000° C., as shown in FIG. 87. In other embodiments, glass (not limitedto viscous, high temperature amorphous glasses) may be manufactured tohave a granular profile via processes disclosed herein, such as wherethe sintering temperatures are low enough to leave individual grains orportions thereof, as shown with silica above in FIGS. 79A, 79B, and 80.The granular profile may be useful for light scattering, for example.Still other embodiments may include glasses such as chalcogenide, orglasses that have little or no silica, which may be viscous, hightemperature glasses.

Use of slurries for green tape and the sintering system disclosed hereinmay help make glass with low solid inclusion levels via purificationprocesses and also low seed or low gaseous inclusion levels. Forexample, liquid filtering of the slurry prior to casting is one suchprocess, such as for example where sub-micron (e.g., 22 m²/g) powdermixed in the solvents may be filtered through different size filters (40to 200 μm sieves for example) in order to capture larger size soliddefects, such as solid oxide debris or organic debris such as hair.Also, debris may be removed via different settling rates in suspensions,such as where higher density agglomerated particles settle faster thandispersed silica and lighter organic impurities rise to the surface. Amiddle percentage, such as the middle 80%, could then be used to cast.Centrifuges may accelerate the settling or rising process.

Uniform, consistent and filtered slurry that has been thoroughly degased(or de-aired) prior to casting to create a very uniform and consistenttape may help minimize the seed levels. Index matching tapes may alsofacilitate detection of both seeds and solid inclusions. The binder burnout step described above, to remove organics, may occurs at temperaturesless than 700° C., and oxygen at elevated temperatures may help removefinal residues of carbon, which could be trapped or react with silica tocreate gases such as CO or CO₂ and SiO.

The particularly thin forms of at least some articles described hereinhave short permeation paths for gases, which result in very littletrapped gases even when air is used. To further minimize trapping ofinsoluble gases such as argon, nitrogen, and (to a lesser extent)oxygen, consolidation in an air free atmosphere may be used, such as invacuum and/or vacuum with helium or hydrogen, or atmospheric helium orhydrogen, or mixtures thereof. If the consolidating glass has trappedthese gases (helium or hydrogen), then the gases may permeate out of thestructure in minutes or seconds at any reasonable temperature greaterthan 1000° C. and leave behind a vacuum or seed with no gases present.The seed may then collapse from atmospheric pressure combined withcapillary stresses at temperatures where glass deformation occur. Inmost, seed minimization would take place preferably during theconsolidation operation, prior to annealing. However, the glass could bereheated to outgas trapped gas, collapsed the seeds, and then annealed.Accordingly, at least some embodiments include glass articles (e.g.,rolls, tapes, sheets) with little to no trapped gas, such as less than5% by volume, such as less than 3% by volume, such as less than 1% byvolume.

Some embodiments of the present invention, as disclosed above, may userollers within the sintering furnace to control tension, speed,deformation, or other attributes of the article (e.g., tape or ribbon)during sintering. According to some embodiments, the rollers rotate atdifferent speeds from one another, such as a function of shrinkage ofthe respective article. For example, in at least one embodiment thefurnace includes at least two rollers, wherein a first roller interfaceswith a less sintered portion of the article, and the second rollerinterfaces with a more sintered portion of the article. The secondroller rotates at a slower speed than the first roller. In some suchembodiments, rotation of the roller(s) within the furnace correspond tofree body sintering rates of the respective article being sintered, orhave a slightly greater speed to impart tension in the article, such asto flatten the article or control warp. The rollers may be made fromrefractory materials. Stationary supports (e.g., furnace floor) may belocated between rollers in the furnace. In contemplated embodiments,multiple rows of rollers at different levels within the furnace may beused, such as to increase output and/or control airflow within thefurnace. Such rollers may be used with lengths of rigid materials, suchas rods or sheets.

FIGS. 88A to 88B show an embodiment of such a sintering system. Morespecifically, FIG. 88A shows a sintering temperature versus distancethrough the furnace of FIG. 88B for sintering yttria-stabilizedzirconia. The article (e.g., ribbon, tape) moves from left to rightthrough the furnace, from a first roll as an unfired sheet (or lesssintered tape) to a second roll as a sintered ceramic sheet (or moresintered tape). Through the furnace are rotating surfaces in the form ofrollers that rotate with normalized speeds ranging from 1.0 to 0.78,which are a function of the rate of shrinkage of the yttria-stabilizedzirconia. FIG. 89 shows a furnace with intermediate rollers, as shown inFIGS. 88A and 88B, but with multiple levels. In some embodiments, asintering station or other furnace as disclosed herein includes morethan one tape or ribbon traversing the furnace at the same time.Referring to FIGS. 90A and 90B, in other contemplated embodiments,moving (e.g., rotating) surfaces within the furnace, other than rollersas disclosed above, include belts, tracks, or other elements. Someembodiments may include only a single belt or loop of tracks.

Referring to FIGS. 91A and 91B, an article (e.g., tape as describedabove, sheet, etc.) comprises a lithium-containing ceramic, specificallysintered Li_(6.1)La₃Zr₂Al_(0.3)O₁₂ manufactured using technologydisclosed above. An excess lithium source, in the form of 6.7 wt %Li₂CO₃, cast at 6 mil in acrylic binder (e.g., produced by Elvacite) wasprocessed in a binder burnout furnace with five heat zones attemperatures of 180, 225, 280, 350, and 425° C., respectively, at a rateof 4 inches per minute. The article was then sintered at 1125° C. Theresulting sintered article, as shown in FIGS. 91A and 91B, consisted ofgreater than 80 percent by weight (wt %) cubic lithium garnet crystals,such as greater than 90 wt %, such as greater than 95 wt %, such asconsisted of about 99 wt % cubic lithium garnet crystals, as measured byx-ray diffraction. Traditional approaches of sintering of lithiumgarnet, such as batch sintering in a sealed crucibles, typically resultin higher percentages of non-cubic crystals. The resulting sinteredarticle, as shown in FIGS. 91A and 91B, had an ionic conductivity, asmeasured by complex impedance analysis of greater than 5×10⁻⁵ S/cm, suchas greater than 1×10⁻⁵ S/cm, such as about 1.72×10⁻⁵ S/cm. The resultingsintered article, as shown in FIGS. 91A and 91B, had less than 10percent by volume (vol %) porosity, such as less than 5 vol %, and/orthe corresponding porosity comprised at least some, most, at least 80%,at least 90% closed porosity, meaning that pores were completely sealedoff. Applicants believe such characteristics are due to the fast firing,tension control, air flow control, and other technology disclosedherein.

Referring to FIG. 92, an article comprises a lithium-containing ceramic,specifically sintered Li_(5.39)La₃Zr_(1.7)W_(0.3)Ga_(0.5)O_(x) with“excess” lithium from 10.7 wt % Li₂CO₃ cast at 12 mil (“mil” is onethousandth of an inch) in acrylic binder and sintered at 1050° C. withthe above-described technology. The image in FIG. 92 is not polished,but shows closed porosity and “pull-out” grains. Applicants haveobserved that the sintering system of the present disclosure may resultsmaller grains in sintered lithium-containing ceramic (garnet) whencompared to conventional sintering of “pills” in sealed crucibles. Forexample, some articles of lithium-containing garnet of the presentdisclosure have a grain size of 5 μm or less, such as 3 μm or less. By“grain size,” Applicants are referring to ASTM E-112-13 “Standard TestMethods for Determining Average Grain Size,” using the basic linearintercept method, sections 12, 13 and 19 as well as Paragraph A2.3.1,using Equation A2.9 average grain size is 1.5 times average interceptlength for a spherical assumption of grain shape. Smaller grain sizesmay yield higher strength tapes or other articles, which may be rolledwithout fracture on diameters of cores disclosed herein. With that said,tapes or other articles of lithium-containing ceramics may be producedusing technology disclosed herein with larger grain sizes, such as bystarting with larger grains or increasing sintering time.

In some embodiments, a lithium-containing garnet article (e.g., sheet,tape) of the present disclosure may be integrated in electronics, suchas a solid state lithium battery as an electrolyte, such as positionedbetween an anode and cathode, as shown in FIG. 93 for example, with anelectrically-conductive metal current collector coupled to (e.g., bondedto, overlaying) the lithium-containing garnet article, such as by way ofthe anode and/or cathode. In other electronics, such as packagingcomponentry, a metal layer may be directly bonded to, as in directcontact with, a ceramic article as disclosed above. In contemplatedembodiments, the anode and/or the cathode may be tape cast as a greentape and co-fired with the electrolyte, which may improve performance ofthe electronics by enhancing electrolyte interface(s) with the anodeand/or cathode. Accordingly, articles as disclosed herein may compriselayers, with thicknesses described above for each layer (e.g., 100 μm orless per layer) of two or more different inorganic materials asdisclosed herein sintered from green tape and directly contacting andoverlaying one another and fired as disclosed above, as a thin co-firedtape for example. The lithium-containing garnet in the electronics hasclosed pores, few defects (as disclosed above), few or no pin holes,ionic conductivity (as disclosed above), and/or small grain size (asdisclosed above).

Referring to FIGS. 94 and 95, two example firing cycles forlithium-containing are shown. Such temperature versus time profiles maybe implemented by rate of moving articles, as disclosed herein, throughthe presently disclosed sintering system, and by controlling heat zoneswithin the system to provide such heating. Alternatively, shorter lengtharticles may be moved into and out of furnaces as disclosed herein, andheld stationary within such furnaces to control sintering time, forexample. As shown in FIGS. 93 and 94, sintering time (i.e. time attemperatures that induce sintering) is relatively short, such as lessthan 2000 seconds per cycle. In some embodiments, the same article maybe sintered in multiple cycles, such as in a first cycle at a firstlevel of tension and first peak temperature, and then in a second cycleof different tension, temperature, and/or time cycle time, which mayhelp control distortion of the article due to shrinkage duringsintering.

Applicants have found that use of “excess” volatile constituents (e.g.,lithium) in the green material greatly improves resulting ceramic tape.For example, without excess lithium, lithium lost from garnet due tovaporization may result in a second phase material, such as La₂Zr₂O₇“pyrochlore,” which may act as an insulator and inhibit sintering.Accordingly, ceramic with pyrochlore may result the material that ishighly porous, mechanically weak, and/or has poor conductivity. Putanother way, Applicants believe that cubic phase, sintering extent anddensity (inverse of porosity), strength, and ionic conductivity alldecrease as pyrochlore phase increases, such as from lithium loss.

FIGS. 96 and 97 show ionic conductivity (FIG. 96) and weight percentageof cubic garnet for Li_(5.39)La₃Zr_(1.7)W_(0.3)Ga_(0.5)O_(x) with 10.7wt % Li₂CO₃ as a source of excess lithium, as described above, eitherpre-reacted (“PR”) or not, with a 3 minute sintering time, as shown inFIG. 94, or a 15 minute sintering time, as shown in FIG. 95. The opendots in FIG. 96 are interpolated. Each of the examples in FIG. 96 hadionic conductivity of greater than 5×10⁻⁵ S/cm, and some had greaterthan 2×10⁻⁴ S/cm, such as greater than 3×10⁻⁴ S/cm. Surprisingly, theshorter sintering times generally resulted in higher ionic conductivity,which may be synergistic in terms of production efficiency. Referring toFIG. 97, each of the examples had greater than 90 wt % cubic garnet,such as greater than 93 wt % cubic garnet, and some had greater than 95wt %. By comparison, Li_(6.1)La₃Zr₂Al_(0.3)O₁₂ with 6.7 wt % Li₂CO₃excess lithium source cast at 6 mil in acrylic binder and sintered at1030° C. resulted in 33 wt % cubic and 3.84×10⁻⁶ S/cm conductivity.

In other examples, Li_(6.5)La₃Zr_(1.5)Ta_(0.5)O₁₂ with 11.98 wt % Li₂CO₃added in the slip of the tape cast, cast with 10 mil blade, had binderburned off in an argon atmosphere, and then was sintered using thetechnology disclosed herein for 15 or 8 minutes in air. FIGS. 85A and85B show a green tape of Li_(6.5)La₃Zr_(1.5)Ta_(0.5)O₁₂ with 11.98 wt %Li₂CO₃, where the unfired median particle size (D₅₀) about 0.60micrometers, the tape thickness was about 85 to 88 micrometers, and theslip was about 18 vol % solid. FIGS. 98 and 99 show micrographs of acorresponding sintered tape after 15 minutes sintering at about 1200° C.The sintered tape of FIGS. 98 and 99 is about 54 micrometers thick dueto about 37 to 38% shrinkage. As can be seen in FIG. 99, the tapeincludes some closed pores but no pin holes. FIGS. 100A and 100B showmicrographs of a first major surface of the sintered tape of FIGS. 98and 99, and FIGS. 101A and 101B show the second major surface. Thesurfaces have a granular profile. Grain size is between about 1 to 5micrometers, on average, with some grains as large as about 10micrometers. Ionic conductivity was measured to be 3.83×10⁻⁴ S/cm usingstandard complex impedance analysis. Phase quantification showed 96 wt %cubic garnet. For a similar sample instead sintered for 8 minutes, about100 wt % cubic garnet. In another Li_(6.5)La₃Zr_(1.5)Ta_(0.5)O₁₂ sample,with instead 6.7% excess Li₂CO₃ added and sintered at 1150° C. for 3minutes, conductivity was about 1.18×10⁻⁴ S/cm. Some lithium-containingceramics included silicone added to the green tape that became silica inthe sintered article, which Applicants believe may strengthen thesintered article, such as 2 wt % M97E Silicone (SILRES®) added to theMAA with 10.7 wt % Li₂CO₃, and sintered at 1050° C. for 3 minutes,resulting in 2.38×10⁻⁴ S/cm conductivity. When sintered at 1100° C. for3 minutes, the same material combination had 2.59×10⁻⁴ S/cmconductivity. In another example 7 wt % of LiOH excess lithium sourcewas added to MAA and sintered at 1200° for 3 minutes, resulting in1.97×10⁻⁴ S/cm conductivity.

As indicated above, the present technology (e.g., binder burn-off,sintering station with multi-heat zones and air flow control, tensioncontrol, etc.) may be used to sinter green material (tape or otherarticles) to have the structures, geometries, and properties/attributesdisclosed herein, such as green material that includes an organic binder(e.g., polyvinyl butyral, dibutyl phthalate, polyalkyl carbonate,acrylic polymers, polyesters, silicones, etc.) supporting particles ofinorganic material, such as polycrystalline ceramic, synthetic mineral,viscous glasses that may be hard to otherwise process into a thin tapeor ribbon structure for roll-to-roll manufacturing, or other inorganicmaterials (e.g., metals, less viscous glasses). For example, theinorganic materials include zirconia (e.g., yttria-stabilized zirconia,nickel-yttria stabilized zirconia cermet, NiO/YSZ), alumina, spinel(e.g., MgAl₂O₄, zinc ferrite, NiZn spinel ferrite, or other mineralsthat may crystallize as cubic and include the formulation of A₂₊B₂ ³⁺O₄²⁻, where A and B are cations and may be magnesium, zinc, aluminum,chromium, titanium, silicon, and where oxygen is the anion except forchalcogenides, such as thiospinel), silicate minerals such as garnet(e.g., lithium garnet or lithium-containing garnet, of formulaX₃Z₂(TO₄)₃ where X is Ca, Fe, etc., Z is Al, Cr, etc., T is Si, As, V,Fe, Al), lithium lanthanum zirconium oxide (LLZO), cordierite, mullite,perovskite (e.g., porous perovskite-structured ceramics), pyrochlore,silicon carbide, silicon nitride, boron carbide, sodium bismuthtitanate, barium titanate (e.g., doped barium titanate), magnesiumtitanium oxide, barium neodymium titanate, titanium diboride, siliconalumina nitride, aluminum nitride, silicon nitride, aluminum oxynitride,reactive cerammed glass-ceramic (a glass ceramic formed by a combinationof chemical reaction and devitrification, which includes an in situreaction between a glass frit and a reactant powder(s)), silica, dopedsilica, ferrite (e.g., NiCuZnFeO ferrite, BaCO ferrite),lithium-containing ceramic, including lithium manganate, lithium oxide,viscous glasses as discussed above, such as high-melting temperatureglasses, glasses with a Tg greater than 1000° C. at standard atmosphericpressure, high purity fused silica, silica with an SiO₂ content of atleast 99% by volume, silica comprising a granular profile, a silica tapewithout a repeating pattern of waves or stria extending across a widthof the tape, iron sulfide, piezoelectric ceramic, potassium niobate,silicon carbide, sapphire, yttria, cermet, steatite, forsterite,lithium-containing ceramics (e.g., gamma-LiAlO₂), transition metal oxide(e.g., lithium manganite, which may also be a spinel, ferrite),materials with volatile constituents as described above (e.g., lithiummanganite (again)) lead oxide, garnets, alkali-containing materials,sodium oxide, glass-ceramic particles (e.g. LAS lithiumaluminosilicates), and other inorganic materials as disclosed herein orotherwise.

In contemplated embodiments, inorganic binders like colloidal silica,alumina, zirconia, and hydrates thereof may be used in place of or incombination with organic binders as disclosed herein, such as tostrengthen the tape. Applicants have found that stronger tape makes thesintering process more robust in terms of stability and access to awider process space, such as greater tension. In some embodiments, agreen material (e.g., green tape) as used herein, includes an inorganicbinder. For example, a source of tape material may comprise a green tapeand a carrier web supporting the green tape, the green tape comprisinggrains of inorganic material and an inorganic binder in an organicbinder. In some embodiments, inorganic particles, such as inorganicbinder includes particles of about 5 nm to about 100 micrometers in D₅₀particle size.

In contemplated embodiments, materials, such as ceramics disclosedherein, may be fired to have a high degree of porosity, such as greaterthan 20% by volume, such as greater than 50%, such as greater than 70%,and/or such materials may then be filled with a polymeric filler. Use ofpartially sintered inorganic material, as disclosed herein may haveadvantages over loose inorganic material in a composite because thepartially sintered inorganic material may serve as a rigid skeleton tohold shape of the composite at high temperatures where the polymericfiller softens. Accordingly, some embodiments include a composite tapehaving dimensions disclosed above, of partially sintered ceramic, where(at least some, most, almost all) particles are the ceramic are sinteredto one another and/or where porosity of the ceramic is at leastpartially, mostly, or fully filled with a polymer filler.

As indicated above, in some embodiments different inorganic materialsmay be co-fired using technology disclosed herein, such as discretelayers of the different inorganic materials (e.g., anode pluselectrolyte of solid state battery), or in other arrangements, such asan evenly distributed mixture of two or more inorganic materialsco-fired, such as to influence thermal expansion, strength, or othercharacteristics of the resulting article. In some embodiments, glass andceramic may be co-fired, such as where a glass phase is mixed withparticles of ceramic. For example, FIG. 102 shows low-temperatureco-fired ceramic tape (glass and alumina) sintered at 1000° C. using asintering station comprising an air bearing such that the tape wassintered without direct contact with walls/floors in the furnace.

Some embodiments of the present disclosure include an article (e.g.,sheet, tape or ribbon), such as of inorganic material, such as ceramic,such as alumina or zirconia, with a granular profile and a layer (orcoating) overlaying the granular profile to reduce roughness of thegranular profile, such as on one or more major surfaces of the article.The layer may be applied in a liquid form through spin coating, slot diecoating, spray coating, dip coating, or other processes. In someembodiments, the layer may be amorphous and inorganic, such as glass orconverted into solid glass upon thermal annealing or curing. In somesuch embodiments, the layer is mostly silicon and oxygen, such as withsome phosphorous, boron, carbon, nitrogen or other constituents. Thelayer may also include oxides of Ti, Hf, and/or Al. Such a layer may beapplied and cured as part of the same manufacturing line as the binderburnout and sintering, and the resulting article (e.g., tape) may berolled and include the layer when rolled. In some embodiments, the layeris annealed at temperatures of 850° C. or higher and is very thin, suchas a positive thickness less than a micrometer, such as less than 560nm. In some embodiments, roughness of the layer is less than half thatof the granular profile, such as less than a third. In some embodiments,roughness of the layer is less than 15 nm, such as about 5 nm averageroughness (Ra or Rq) over a distance of 1 cm along a single axis.

In yttrium-stabilized zirconia and alumina articles were laser cut into30×30 mm squares and coated by spin-on-glass, spin coating techniques. Apure silica solution (Desert Silicon NDG series) was tested along with alightly doped (10²¹ atoms/cm³) phosphorous-doped silica solution (DesertSilicon P-210). The solution was applied in a liquid form, and uponcuring solidified. A final anneal densified the glass film. Thesolutions were applied using spin coating. Samples were then curedeither in a hot plate at temperatures between 150° C. and 200° C. or ina vacuum oven with temperatures between 170° C. and 250° C. After theinitial cure, samples were annealed in nitrogen atmosphere attemperatures between 850° C. and 1000° C. One-inch square silicon pieceswere processed in parallel to the ceramic pieces to provide “witness”samples, used to accurately measure the glass film thickness usingoptical ellipsometer.

In one example a sheet of 40 μm thick alumina was coated withphosphorous-doped silica (Desert Silicon P210) by spinning at 1500revolutions per minute (rpm) for 60 seconds, with 133 rpm/secondacceleration, resulting in a coating of about 320 nm thick, 15.3 nm Ra,12.1 nm Rq, 130 nm Z_(max) on one side and 25.9 nm Ra, 20 nm Rq, and 197nm Z_(max) on the other, where the coated layer had good film qualityafter furnace anneal at 850° C., with no cracking. In another example asheet of 40 μm thick alumina was coated with non-doped silica (DesertSilicon NDG-2000) by spinning at 1500 revolutions per minute (rpm) for60 seconds, with 133 rpm/second acceleration, resulting in a coating ofabout 444 nm thick, 11 nm Ra, 8.8 nm Rq, 79.4 nm Z_(max) on one side and22.6 nm Ra, 17 nm Rq, and 175 nm Z_(max) on the other, again where thecoated layer had good film quality after furnace anneal at 850° C., withno cracking. By contrast, in another example a sheet of 40 μm thickalumina was coated with non-doped silica (Desert Silicon P210) byspinning at 4000 revolutions per minute (rpm) for 60 seconds, with 399rpm/second acceleration, resulting in a coating of about 946 nm thick,5.1 nm Ra, 6.5 nm Rq, 48 nm Z_(max) on one side and 10.8 nm Ra, 14 nmRq, and 89 nm Z_(max) on the other, where the coated layer hadpronounced cracking after furnace anneal at 850° C.

In one example a sheet of 40 μm thick yttria-stabilized zirconia wascoated with non-doped silica (Desert Silicon NDG-2000) by spinning at2000 revolutions per minute (rpm) for 60 seconds, with 1995 rpm/secondacceleration, resulting in a coating of about 258 nm thick, 5.9 nm Ra,4.7 nm Rq, 92 nm Z_(max) on one side, where the coated layer had goodfilm quality after furnace anneal at 1000° C. for 60 minutes, with nocracking. In another example a sheet of 40 μm thick yttria-stabilizedzirconia was coated with phosphorous-doped silica (Desert Silicon P210)by spinning at 1500 revolutions per minute (rpm) for 60 seconds, with133 rpm/second acceleration, resulting in a coating of about 320 nmthick, 8.9 nm Ra, 11.7 nm Rq, 135 nm Z_(max) on one side, again wherethe coated layer had good film quality after furnace anneal at 850° C.for 30 minutes, with no cracking. By contrast, in another example asheet of 40 μm thick yttria-stabilized zirconia was coated withnon-doped silica (Desert Silicon P210) by spinning at 1500 revolutionsper minute (rpm) for 60 seconds, with 133 rpm/second acceleration,resulting in a coating of about 444 nm thick, 7.7 nm Ra, 9.5 nm Rq, 75nm Z_(max) on one side, where the coated layer had some cracking afterfurnace anneal at 850° C. Surface morphology of the samples was measuredusing Atomic-Force-Microscopy on a 10 micron field of view. FIG. 103,for example, shows an electron microscope image of pure silica (DesertSilicon NDG-2000) coated yttria-stabilized zirconia. The layer of silicais about 250 nm thick. Such layers may improve dielectric properties ofthe tape, and/or serve as a barrier layer to prevent transmission ofimpurities to/from the underlying material. For example, such layers maybe used with LEDs, as disclosed above, or other electronics andpackaging, and/or may be applied to sintered tape and rolled as a rollof the tape, as disclosed herein. In other contemplated embodiments, thelayer may be another inorganic material, or a polymeric material, suchas for different uses.

Aspects of the present disclosure relate to a sintered article thatcomprises (1) a first major surface, (2) a second major surface opposingthe first major surface, and (3) a body extending between the first andsecond surfaces, where the body comprises a sintered inorganic material,where the body has a thickness (t) defined as a distance between thefirst major surface and the second major surface, a width defined as afirst dimension of one of the first or second surfaces orthogonal to thethickness, and a length defined as a second dimension of one of thefirst or second surfaces orthogonal to both the thickness and the width,and where the width is about 5 mm or greater, the thickness is in arange from about 3 μm to about 1 mm, and the length is about 300 cm orgreater. This sintered article may be such that the inorganic materialcomprises an interface having a major interface dimension of less thanabout 1 mm, where the interface comprises either one of or both achemical inhomogeneity and crystal structure inhomogeneity, andoptionally where the inorganic material comprises a ceramic material ora glass ceramic material and/or where the inorganic material comprisesany one of a piezoelectric material, a thermoelectric material, apyroelectric material, a variable resistance material, or anoptoelectric material. In some such embodiments, the inorganic materialcomprises one of zirconia, alumina, spinel, garnet, lithium lanthanumzirconium oxide (LLZO), cordierite, mullite, perovskite, pyrochlore,silicon carbide, silicon nitride, boron carbide, sodium bismuthtitanate, barium titanate, titanium diboride, silicon alumina nitride,aluminum oxynitride, or a reactive cerammed glass-ceramic. In any one ofthe above sintered articles, the sintered article may comprise at leastten square centimeters of area along the length that has a compositionwhere at least one constituent of the composition varies by less thanabout 3 weight %, across the area; and/or where the sintered articlecomprises at least ten square centimeters of area along the length thathas a crystalline structure with at least one phase having a weightpercent that varies by less than about 5 percentage points, across thearea; and/or where the sintered article comprises at least ten squarecentimeters of area along the length that has a porosity that varies byless than about 20%; and/or where one or both the first major surfaceand the second major surface has a granular profile comprising grainswith a height in a range from 25 nm to 150 μm relative to recessedportions of the respective surface at boundaries between the grains;and/or where one or both the first major surface and the second majorsurface has a flatness in the range of 100 nm to 50 μm over a distanceof one centimeter along the length or the width; and/or where one of orboth the first major surface and the second major surface comprises atleast ten square centimeters of area having fewer than one hundredsurface defects from adhesion or abrasion with a dimension greater than5 μm, such as optionally where the other of the first major surface andthe second major surface comprises surface defects from adhesion orabrasions with a dimension of greater than 5 μm; and/or furthercomprising a striated profile along the width dimensions, wherein thethickness is within a range from about 0.9t to about 1.1t, such as wherethe striated profile comprises 2 or more undulations along the widthand/or where the striated profile comprises less than 20 undulationsalong the width.

Aspects of the present disclosure relate to a sintered article,comprising (1) a first major surface, (2) a second major surfaceopposing the first major surface, and (3) a body extending between thefirst and second surfaces, the body comprising a sintered inorganicmaterial,

where the body has a thickness (t) defined as a distance between thefirst major surface and the second major surface, a width defined as afirst dimension of one of the first or second surfaces orthogonal to thethickness, and a length defined as a second dimension of one of thefirst or second surfaces orthogonal to both the thickness and the width,and where (at least) a portion of the sintered article is flattenable.In some such sintered articles, the article, when flattened, exhibits amaximum in plane stress (the absolute value of stress, as measured bythe thin plate bend bending equation) of less than or equal to 25% ofthe bend strength (measured by 2-point bend strength) of the article;and/or the article, when flattened, exhibits a maximum in plane stress(the absolute value of stress, as measured by the thin plate bendbending equation) of less than or equal to 1% of the Young's modulus ofthe article. In some such embodiments, where the article has a thicknessof about 80 μm and a bend radius of greater than 0.03 m, the articleexhibits a maximum in plane stress (the absolute value of stress, asmeasured by the thin plate bend bending equation) of less than or equalto 25% of the bend strength (measured by 2-point bend strength) of thearticle; or where the article has a thickness of about 40 μm and a bendradius of greater than 0.015 m, the article exhibits a maximum in planestress (the absolute value of stress, as measured by the thin plate bendbending equation) of less than or equal to 25% of the bend strength(measured by 2-point bend strength) of the article; or where the articlehas a thickness of about 20 μm and a bend radius of greater than 0.0075m, the article exhibits a maximum in plane stress (the absolute value ofstress, as measured by the thin plate bend bending equation) of lessthan or equal to 25% of the bend strength (measured by 2-point bendstrength) of the article. In some such embodiments, the width of thesintered article is about 5 mm or greater, the thickness is in a rangefrom about 3 μm to about 1 mm, and the length is about 300 cm orgreater, and/or the portion of the sintered article that is flattenablecomprises a length of about 10 cm. In some such embodiments, one or boththe first major surface and the second major surface has a flatness inthe range of 100 nm to 50 μm over a distance of one centimeter along thelength or the width. In some such embodiments, the inorganic materialcomprises a ceramic material or a glass ceramic material; the inorganicmaterial comprises any one of a piezoelectric material, a thermoelectricmaterial, a pyroelectric material, a variable resistance material, or anoptoelectric material; and/or the inorganic material comprises one ofzirconia, alumina, spinel, garnet, lithium lanthanum zirconium oxide(LLZO), cordierite, mullite, perovskite, pyrochlore, silicon carbide,silicon nitride, boron carbide, sodium bismuth titanate, bariumtitanate, titanium diboride, silicon alumina nitride, aluminumoxynitride, or a reactive cerammed glass-ceramic. In some suchembodiments, the sintered article comprises at least ten squarecentimeters of area along the length that has a composition where atleast one constituent of the composition varies by less than about 3weight %, across the area; and/or the sintered article comprises atleast ten square centimeters of area along the length that has acrystalline structure with at least one phase having a weight percentthat varies by less than about 5 percentage points, across the area;and/or the sintered article comprises at least 10 square centimeters ofarea along the length that has a porosity varies by less than about 20%,across the area; and/or one or both the first major surface and thesecond major surface has a granular profile comprising grains with aheight in a range from 25 nm to 150 μm relative to recessed portions ofthe respective surface at boundaries between the grains; and/or one orboth the first major surface and the second major surface has a flatnessin the range of 100 nm to 50 μm over a distance of one centimeter alongthe length or the width; and/or one of or both the first major surfaceand the second major surface comprises have at least ten squarecentimeters of area having fewer than one hundred surface defects fromadhesion or abrasion with a dimension greater than 5 μm, such as wherethe other of the first major surface and the second major surfacecomprises surface defects from adhesion or abrasions with a dimension ofgreater than 5 μm; and/or the sintered article further comprising astriated profile along the width dimensions, wherein the thickness iswithin a range from about 0.9t to about 1.1t, such as where the striatedprofile comprises 2 or more undulations along the width; and/or thearticle comprises a saddle shape; and/or the article comprises a c-shapehaving a concave shape along the length.

Aspects of the present disclosure relate to a rolled sintered articlecomprising (1) a core having a diameter of less than 60 cm and (2) acontinuous sintered article wound around the core, the continuoussintered article comprising (2a) a first major surface, (2b) a secondmajor surface opposing the first major surface, (2c) a body extendingbetween the first and second surfaces, the body comprising a sinteredinorganic material, where the body has a thickness (t) defined as adistance between the first major surface and the second major surface, awidth defined as a first dimension of one of the first or secondsurfaces orthogonal to the thickness, and a length defined as a seconddimension of one of the first or second surfaces orthogonal to both thethickness and the width, and where the width is about 5 mm or greater,the thickness is in a range from about 3 μm to about 1 mm, and thelength is about 30 cm or greater. In some such embodiments, thecontinuous sintered article is disposed on an interlayer supportmaterial, and the continuous sintered article and interlayer supportmaterial are wound around the core such that each successive wrap of thecontinuous sintered article is separated from one another by theinterlayer support material, such as where the interlayer supportmaterial comprises a first major surface and a second major surfaceopposing the first major surface, an interlayer thickness (t) defined asa distance between the first major surface and the second major surface,an interlayer width defined as a first dimension of one of the first orsecond surfaces orthogonal to the interlayer thickness, and aninterlayer length defined as a second dimension of one of the first orsecond major surfaces orthogonal to both the interlayer thickness andthe interlayer width of the interlayer support material, and where theinterlayer thickness is greater than the thickness of the sinteredarticle and/or where the inlayer comprises a tension that is greaterthan a tension on the continuous sintered article, as measured by a loadcell, and/or where the rolled article comprises a diameter and a sidewall width that are substantially constant, and/or where the corecomprises a circumference and a core centerline along the circumference,where the continuous sintered article comprises an article centerlinealong a direction of the length, and where distance between the corecenterline and the article centerline is 2.5 mm or less, along thelength of the continuous sintered article, and/or where the interlayersupport material is compliant, and/or where the interlayer width isgreater than the width of the continuous sintered article, and/or wherethe interlayer support material comprises any one or both a polymer anda paper, such as where the polymer comprises a foamed polymer, such aswhere the foamed polymer is closed cell.

Aspects of the present disclosure relate to a plurality of sinteredarticles each comprising (1) a first major surface, (2) a second majorsurface opposing the first major surface, and (3) a body extendingbetween the first and second surfaces, the body comprising a sinteredinorganic material, where the body has a thickness (t) defined as adistance between the first major surface and the second major surface, awidth defined as a first dimension of one of the first or secondsurfaces orthogonal to the thickness, and a length defined as a seconddimension of one of the first or second surfaces orthogonal to both thethickness and the width, and where each of the plurality of sinteredarticles is flattenable. In some such embodiments, each article, whenflattened, exhibits a maximum in plane stress (the absolute value ofstress, as measured by the thin plate bend bending equation) of lessthan or equal to 25% of the bend strength (measured by 2-point bendstrength) of the article; and/or each article, when flattened, exhibitsa maximum in plane stress (the absolute value of stress, as measured bythe thin plate bend bending equation) of less than or equal to 1% of theYoung's modulus of the article. In some such embodiments, where eacharticle has a thickness of about 80 μm and a bend radius of greater than0.03 m, the article exhibits a maximum in plane stress (the absolutevalue of stress, as measured by the thin plate bend bending equation) ofless than or equal to 25% of the bend strength (measured by 2-point bendstrength) of the article; and/or where each article has a thickness ofabout 40 μm and a bend radius of greater than 0.015 m, the articleexhibits a maximum in plane stress (the absolute value of stress, asmeasured by the thin plate bend bending equation) of less than or equalto 25% of the bend strength (measured by 2-point bend strength) of thearticle; and/or where the article has a thickness of about 20 μm and abend radius of greater than 0.0075 m, the article exhibits a maximum inplane stress (the absolute value of stress, as measured by the thinplate bend bending equation) of less than or equal to 25% of the bendstrength (measured by 2-point bend strength) of the article. In somesuch embodiments, the thickness of the plurality of sintered articles iswithin a range from about 0.7t to about 1.3t; and/or at least 50% of thesintered articles comprises an area and a composition, where at leastone constituent of the composition varies by less than about 3 weight %across the area; and/or at least 50% the sintered articles comprise anarea and a crystalline structure with at least one phase having a weightpercent that varies by less than about 5 percentage points across thearea; and/or at least 50% of the sintered articles comprise an area anda porosity that varies by less than about 20% across the area.

Aspects of the present disclosure relate to a separation system forseparating two materials, where the separation system comprises a sourceof a continuous tape material comprising a green tape material and acarrier web supporting the green tape material; a vacuum drum positionedin proximity to the source of a continuous tape material and configuredto receive and convey the continuous material from the source to apeeler, where the vacuum drum comprises a plurality of vacuum holes forfacilitating applying tension by the separation system to the carrierweb that is greater than a tension applied to the green tape material,as the continuous roll is conveyed to the peeler; and a peeler fordirecting the carrier web in a rewind direction and directing the greentape material in a downstream processing direction that differs from therewind direction. In some such embodiments, the source of continuoustape material comprises a spool or a belt comprising the continuousmaterial wound thereon. In some embodiments, the rewind and downstreamprocessing directions form an angle therebetween that is greater thanabout 90 degrees. In at least some of such embodiments, the separationsystem applies essentially no tension to the green tape material(excluding weight of the green tape itself). In at least some of suchembodiments, the tension applied to the carrier web at least 2 timesgreater than the tension applied to the green tape material. In at leastsome of such embodiments, the peeler comprises a tip that separates thecarrier web from the green tape material before directing the carrierweb in a rewind direction and directing the green tape material in adownstream processing direction that differs from the rewind direction.In at least some of such embodiments, the peeler comprises a tip thatseparates the carrier web from the green tape material simultaneouslywith directing the carrier web in a rewind direction and directing thegreen tape material in a downstream processing direction that differsfrom the rewind direction, where the tip may comprise a radius of about0.05 inches or less. In at least some of such embodiments, theseparation system further comprises a furnace for sintering the greentape material, an uptake reel for spooling the carrier web, and/or aload controller for maintaining the tension on the carrier web.

Other aspects of the present disclosure include a separation system forseparating two materials, which comprises a source of a continuous tapematerial comprising a green tape material disposed on a carrier web, thecarrier web comprising a first tension; a tension isolator positioned inproximity to the source configured to apply a second tension to carrierweb that is greater than the first tension when conveying the continuousmaterial to a peeler; and a peeler for directing the carrier web in arewind direction and directing the green tape material in a downstreamprocessing direction that differs from the rewind direction. In at leastsome of such embodiments (any one or more of the above embodiments), thesource comprises a spool or a belt comprising the continuous material.In at least some of such embodiments, the rewind direction and thedownstream processing direction form an angle that is greater than about90 degrees. In at least some of such embodiments, the second tension isabout 2.5 pounds per linear inch of width or less. In at least some ofsuch embodiments, the first tension is equal to or less than about 50%of the second tension. In at least some of such embodiments, the peelercomprises a tip that separates the carrier web from the green tapematerial before directing the carrier web in a rewind direction anddirecting the green tape material in a downstream processing directionthat differs from the rewind direction; and/or the tip that separatesthe carrier web from the green tape material simultaneously withdirecting the carrier web in a rewind direction and directing the greentape material in a downstream processing direction that differs from therewind direction; where in neither, either, or both such embodiments thetip comprises a radius of about 0.05 inches or less. In at least some ofsuch embodiments, the tension isolator comprises a vacuum drumcomprising a plurality of vacuum holes that apply the second tension tothe carrier web. In at least some of such embodiments, the separationsystem further comprises a furnace for sintering the green tapematerial, an uptake reel for spooling the carrier web, and/or a loadcontroller for maintaining the tension on the carrier web.

Aspects of the present disclosure relate to a method for separating twomaterials, the method comprising steps, not necessarily in the followingorder, of (1) feeding a continuous material to a tension isolator, thecontinuous material comprising a green tape material disposed on acarrier web, (2) applying tension to the carrier web that is greaterthan a tension applied to the green tape material with the tensionisolator, and (3) directing the carrier web to move in a rewinddirection and directing the green tape material in a downstreamprocessing direction that differs from the rewind direction. In at leastsome such embodiments, the method further comprises a step of separatingthe carrier web from the green tape material before directing thecarrier web in a rewind direction and directing the green tape materialin a downstream processing direction that differs from the rewinddirection, and/or separating the carrier web from the green tapematerial simultaneously with directing the carrier web in a rewinddirection and directing the green tape material in a downstreamprocessing direction that differs from the rewind direction, such aswhere the rewind direction and the downstream processing direction forman angle that is greater than about 90 degrees. In at least some suchembodiments, the method further comprises a step of applying essentiallyno tension to the green tape material, such as where the tension appliedto the carrier web at least 2 times greater than the tension applied tothe green tape material. In at least some such embodiments, the methodfurther comprises a step of at least partially sintering the green tapematerial. In at least some such embodiments, the method furthercomprises a step of spooling the carrier web onto an uptake reel. In atleast some such embodiments, the method further comprises a step ofmaintaining the tension on the carrier web.

Aspects of the present disclosure relate to a method for separating twocontinuous materials, where the method comprises steps, not necessarilyin the following order, of (1) feeding a continuous tape materialcomprising a green tape supported on a carrier web to a tension isolatorand applying a first tension to the carrier web; (2) applying a secondtension to the carrier web that is greater than the first tension; and(3) directing the carrier web to move in a rewind direction anddirecting the green tape material in a downstream processing directionthat differs from the rewind direction. In at least some suchembodiments, the method further comprises a step of separating thecarrier web from the green tape material before directing the carrierweb in a rewind direction and directing the green tape material in adownstream processing direction that differs from the rewind directionand/or separating the carrier web from the green tape materialsimultaneously with directing the carrier web in a rewind direction anddirecting the green tape material in a downstream processing directionthat differs from the rewind direction, such as where the rewinddirection and the downstream processing direction form an angle that isgreater than about 90 degrees. In at least some such embodiments, themethod further comprises a step of applying a first tension comprisesapplying essentially no tension (i.e. very little as disclosed herein).In at least some such embodiments, the second tension is about 2.5pounds per linear inch of width or less. In at least some suchembodiments, the first tension is equal to or less than about 50% of thesecond tension. In at least some such embodiments, the method furthercomprises a step of at least partially sintering the green tapematerial, spooling the carrier web onto an uptake reel, and/ormaintaining the tension on the carrier web.

Aspects of the present disclosure relate to a roll-to-roll tapesintering system, the system comprising (1) an input roll of a length oftape material comprising grains of inorganic material, the inorganicmaterial of the tape material on the input roll having a first porosity;(2) a sintering station comprising (2a) an entrance, (2b) an exit, (2c)a channel extending between the entrance and the exit, and (2d) a heaterheating the channel to a temperature greater than 500 degrees C., wherethe exit, the entrance, and the channel of the sintering station lie ina substantially horizontal plane, such that an angle defined between theexit and the entrance relative to a horizontal plane is less than 10degrees, and where the tape material passes from the input roll, intothe entrance of the sintering station, through the channel of thesintering station and out of the exit of the sintering station and heatwithin the channel sinters the inorganic material of the tape material;and (3) an uptake roll winding the length of tape material followingexit from the sintering station, where the inorganic material of thetape material on the uptake roll has a second porosity that is less thanthe first porosity. In at least some such embodiments, the angle definedbetween the exit and the entrance relative to a horizontal plane is lessthan 1 degree. In at least some such embodiments, the tape material onthe input roll has a width greater than 5 mm and a length greater than10 m. In at least some such embodiments, the tape material on the inputroll has a thickness between 3 microns and 1 millimeter. In at leastsome such embodiments, the tape material moves through the sinteringstation at a high speed of greater than 6 inches per minute. In at leastsome such embodiments, the tape material on the input role includes anorganic binder material supporting the grains of inorganic material, andthe system further comprises (4) a binder removal station locatedbetween the input roll and the sintering station, the binder removalstation comprising (4a) an entrance, (4b) an exit, (4c) a channelextending between the entrance and the exit, and (4d) a heater heatingthe channel to a temperature between 200 degrees C. and 500 degrees C.,wherein the exit of the binder station, the entrance of the binderstation, and the channel of the binder station lie in a substantiallyhorizontal plane such that an angle defined between the exit of thebinder station and the entrance of the binder station relative to ahorizontal plane is less than 10 degrees, where the channel of thebinder station is aligned with the channel of the sintering station suchthat the tape material passes from the input roll, into the entrance ofthe binder removal station, through the channel of the binder removalstation and out of the exit of the binder removal station into theentrance of the sintering station while moving in a substantiallyhorizontal direction, where heat within the channel of the binderremoval station chemically changes and/or removes at least a portion ofthe organic binder material prior to the tape material entering thesintering station. In at least some such embodiments, the heater of thesintering station includes at least two independently controlled heatingelements, the heating elements generate a temperature profile along thelength of the channel of the sintering station that increases along thechannel in a direction from the entrance toward the exit; where in somesuch embodiments the temperature profile is shaped such that stress atedges of the tape material during sintering remains below an edge stressthreshold and such that stress at a centerline of the tape materialduring sintering remains below a centerline stress threshold, where theedge stress threshold and the centerline stress threshold are defined asthose stresses above which the tape material experiences out of planedeformation at the edge and centerline, respectively, of greater than 1mm, such as where the edge stress threshold is less than 300 MPa and thecenterline stress threshold is less than 100 MPa. In at least some suchembodiments, the channel of the sintering station is at least 1 m long.In at least some such embodiments, the sintering station comprises(2d-i) a first sintering furnace defining a first portion of thesintering station channel extending from the entrance of the sinteringstation to an exit opening of the first sintering furnace, (2d-ii) asecond sintering furnace defining a second portion of the sinteringstation channel extending from an entrance opening of the secondsintering furnace to the exit of the sintering station, and (2e) atension control system located between the first sintering furnace andthe second sintering furnace, the tension control system helping toisolate tension between the first and second sintering furnaces, whereintension in the tape material within the second sintering furnace that isgreater than a tension within the tape material in the first sinteringfurnace. In at least some such embodiments, the sintering stationcomprises (2f) an upward facing channel surface defining a lower surfaceof the channel and (2g) a downward facing channel surface defining anupper surface of the channel, where a lower surface of the tape materialis in contact with and slides along the upward facing surface as thetape material moves from the entrance to the exit of the sinteringstation, where the downward facing channel surface is positioned closeto an upper surface of the tape material such that a gap between theupper surface of the tape material and the downward facing channelsurface is less than 0.5 inches, where at least a portion of the upwardfacing channel surface is substantially horizontal measured in thedirection between the entrance and exit of the sintering station suchthat the portion of the upward facing channel surface forms an angle ofless than 3 degrees relative to the horizontal plane. In at least somesuch embodiments, the inorganic material of the tape is at least one ofa polycrystalline ceramic material and synthetic mineral.

Aspects of the present disclosure include a manufacturing furnacecomprising (1) a housing having an upstream face and a downstream face,(2) an entrance opening formed in the upstream face, (3) an exit openingdefined in the downstream face, (4) an upward facing surface locatedbetween the entrance opening and the exit opening, (5) a downward facingflat surface located between the entrance opening and the exit opening,(6) a heating channel extending between the entrance opening and theexit opening and defined between the upward facing surface and thedownward facing surface, (7) a continuous length of tape extending intothe entrance opening, through the heating channel and out of the exitopening, the continuous length of tape comprising: (7a) grains ofinorganic material, (7b) a left edge extending through the heatingchannel the entire distance between the entrance opening and the exitopening, (7c) a right edge extending through the heating channel theentire distance between the entrance opening and the exit opening, and(7d) a centerline parallel to and located between the left edge and theright edge; and (8) a plurality of the independently controlled heatingelements delivering heat to the heating channel generating a temperatureprofile along the length of the heating channel, the temperature profilehaving temperatures greater than 500 degrees C. sufficient to causeshrinkage of the inorganic material of the tape as the tape movesthrough the heating channel, where the temperature profile increasesgradually along at least a portion of the length of the heating channelsuch that the stress within the tape during shrinkage at the left andright edge remain below an edge stress threshold along the entire lengthof the heating channel or stress within the tape material measured atthe centerline remain below a centerline stress threshold along theentire length of the heating channel. In at least some such embodiments,the edge stress threshold is less than 100 MPa and the centerline stressthreshold is less than 100 MPa. In at least some such embodiments, thecontinuous length of tape has an average width greater than 5 mm. In atleast some such embodiments, the entrance opening and the exit openingare aligned with each other in the vertical direction such that astraight line located along the upward facing surface forms an anglerelative to a horizontal plane that is less than 10 degrees. In at leastsome such embodiments, the continuous length of tape moves in adirection from the entrance to the exit and the lower surface of thetape moves relative to the upward facing surface, such as where thelower surface of the tape is in contact with and slides relative to theupward facing surface. In at least some such embodiments, thetemperature profile includes a first section having a first averageslope, a second section having second average slope and a third sectionhave a third average slope, where the first average slope is greaterthan the second average slope, and where the first and second averageslopes are positive slopes and the third average slope is a negativeslope, such as where the first, second and third sections are directlyadjacent with one another and in numerical order, and most or all of thetemperature profile; for example, in at least some such embodiments, thesecond section has a minimum temperature that is greater than 500degrees C. and a maximum temperature that is less than 3200 degrees C.,and extends from the minimum temperature to the maximum temperature overa length of at least 50 inches. In at least some such embodiments, theheating channel is narrow, such that at a cross-section along the lengththereof the maximum vertical distance between the upward facing surfaceand the downward facing surface is less than one inch. In at least somesuch embodiments, the heating channel is divided into at least a firstheating section and second heating section, where a tension controlsystem is located between the first heating section and the secondheating section, where the tension control system at least in partisolates tension in the tape such that tension in the tape materialwithin the second heating section that is greater than tension withinthe tape material in the first heating section. In at least some suchembodiments, the inorganic material of the tape is at least one of apolycrystalline ceramic material and synthetic mineral.

Aspects of the present disclosure relate to a process for forming aspool of sintered tape material comprising steps, not necessarily in thefollowing order, of (1) unwinding a tape from an input reel, the tapecomprising grains of inorganic material and a width greater than 5 mm,(2) moving the unwound length of tape through a heating station, (3)heating the tape within the heating station to a temperature above 500degrees C. such that the inorganic material of the tape is sintered asit moves through the heating station, and (4) winding the tape on anuptake reel following heating and sintering. In at least some suchembodiments, the tape material is held in a substantially horizontalposition during heating. In at least some such embodiments, the tapematerial on the input reel further comprises an organic binder materialsupporting the grains of inorganic material, the process furthercomprising heating the tape material to a temperature between 200degrees C. and 500 degrees C. to remove the binder material before thestep of heating the tape material to a temperature above 500 degrees C.In at least some such embodiments, the width of tape material is greaterthan 10 mm and the length of the tape material is greater than 10 m. Inat least some such embodiments, the tape material is unwound at a speedof at least 6 inches per minute. In at least some such embodiments, theinorganic material is at least one of a polycrystalline ceramic materialand synthetic mineral.

Aspects of the present disclosure relate to a manufacturing system thatcomprises a tape advancing through the manufacturing system, the tapeincluding a first portion having grains of an inorganic material boundby an organic binder; and a station of the manufacturing system thatreceives the first portion of the tape and prepares the tape forsintering by chemically changing the organic binder and/or removing theorganic binder from the first portion of the tape, leaving the grains ofthe inorganic material, to form a second portion of the tape and therebyat least in part prepare the tape for sintering. In at least some suchembodiments, at an instant, the tape simultaneously extends to, through,and from the station such that at the instant the tape includes thefirst portion continuously connected to the second portion. In at leastsome such embodiments, the station chars or burns at least most of theorganic binder, in terms of weight, from the first portion of the tapewithout substantially sintering the grains of the inorganic material. Inat least some such embodiments, the station comprises an active heaterto char or burn at least most of the organic binder from the firstportion of the tape as the tape interfaces with the station to form thesecond portion of the tape, such as where the active heater includesheating zones of different temperatures, such as where the rate of heatenergy received by the tape increases as the tape advances through thestation. In at least some such embodiments, the station is a firststation and the manufacturing system further comprises a second station,where the second station at least partially sinters the inorganicmaterial of the second portion of the tape to form a third portion ofthe tape, such as where, at an instant, the tape includes the firstportion continuously connected to the third portion by way of the secondportion, and/or such as where the first station is close to the secondstation such that distance between the first and second stations is lessthan 10 m, thereby mitigating thermal shock of the second portion of thetape. In at least some such embodiments, the second portion of the tapeis under positive lengthwise tension as the tape advances, such as wherethe lengthwise tension in the second portion of the tape is less than500 grams-force per mm² of cross section. In at least some suchembodiments, the manufacturing system blows and/or draws gas over thetape as the tape advances through the station, such as where the stationheats the tape above a temperature at which the organic binder wouldignite without the gas blown and/or drawn over the tape, whereby theorganic binder chars or burns but the tape does not catch fire, and/orsuch as where flow of the gas blown and/or drawn over the tape as thetape advances through the station is laminar at least over the secondportion of the tape. In at least some such embodiments, the tapeadvances horizontally through the station, and in some such embodimentsthe tape is directly supported by a gas bearing and/or an underlyingsurface and moves relative to that surface as the tape advances throughthe station. In at least some such embodiments, the first portion of thetape is substantially more bendable than the second portion such that aminimum bend radius without fracture of the first portion is less thanhalf that of the second portion.

Aspects of the present technology relate to a furnace to prepare greentape for sintering, the furnace comprising walls defining a passagehaving inlet and outlet openings on opposing ends of the passage, wherethe passage has a length between the inlet and outlet openings of atleast 5 cm, and where the outlet opening is narrow and elongate, havinga height and a width orthogonal to the height, wherein the height isless than a fifth of the width, and wherein the height is less than 2cm; and the furnace further includes a heater that actively providesheat energy to the passage, where the heater reaches temperatures of atleast 200° C. In at least some such embodiments, the furnace is furthercomprising a gas motivator that blows and/or draws gas through thepassage, such as where the gas motivator delivers at least 1 liter ofgas per minute through the passage. In at least some such embodiments,the passage is horizontally oriented, as described above. In at leastsome such embodiments, the heater comprises heat zones that increasetemperature along the passage with distance from the inlet toward theoutlet.

Aspects of the present technology relate to a method of processing tape,comprising steps of (1) advancing a tape through a manufacturing system,the tape including a first portion having grains of an inorganicmaterial bound by an organic binder; and (2) preparing the tape forsintering by forming a second portion of the tape at a station of themanufacturing system by chemically changing the organic binder and/orremoving the organic binder from the first portion of the tape, leavingthe grains of the inorganic material. In at least some such embodiments,at an instant, the tape extends to, through, and from the station suchthat at the instant the tape includes the first portion continuouslyconnected to the second portion. In at least some such embodiments, thestep of preparing the tape for sintering further comprises charring orburning at least most of the organic binder from the first portion ofthe tape without (substantially) sintering the grains of the inorganicmaterial. In at least some such embodiments, the first portion of thetape is substantially more bendable than the second portion such that aminimum bend radius without fracture of the first portion is less thanhalf that of the second portion. In at least some such embodiments, thestation of the manufacturing system is a first station and the method ofprocessing further comprises steps of receiving the second portion ofthe tape at a second station, and at least partially sintering theinorganic material of the second portion of the tape at the secondstation to form a third portion of the tape, such as in at least somesuch embodiments, at an instant, the tape includes the first portioncontinuously connected to the third portion by way of the secondportion. In at least some such embodiments, the process furthercomprises a step of positively tensioning the second portion of the tapeas the tape advances, such as where the step of positively tensioning issuch that lengthwise tension in the second portion of the tape is lessthan 500 grams-force per mm² of cross section. In at least some suchembodiments, the process further comprises a step of blowing and/ordrawing gas over the tape as the tape advances through the station. Inat least some such embodiments, the step of advancing the tape furthercomprises horizontally advancing the tape through the station. In atleast some such embodiments, the process further comprises a step ofdirectly supporting the tape by a gas bearing and/or an underlyingsurface and moving the tape relative to that surface.

Aspects of the present disclosure relate to package comprising: asubstrate; a sintered article comprising a body extending between afirst major surface and a second major surface;

the body comprises a sintered inorganic material, a thickness (t)defined as a distance between the first major surface and the secondmajor surface, a width defined as a first dimension of one of the firstor second surfaces orthogonal to the thickness, and a length defined asa second dimension of one of the first or second surfaces orthogonal toboth the thickness and the width; and the sintered article joineddirectly or indirectly to the substrate. In some such embodiments, thebody width is about 5 mm or greater, the body thickness is in a rangefrom about 3 μm to about 1 mm, and the body length is about 300 cm orgreater. In some such embodiments, the a portion of the sintered articleis flattenable, such as where the sintered article, when flattened,exhibits a maximum in plane stress (the absolute value of stress, asmeasured by the thin plate bend bending equation) of less than or equalto 25% of the bend strength (measured by 2-point bend strength) of thearticle and/or such as where the sintered article, when flattened,exhibits a maximum in plane stress (the absolute value of stress, asmeasured by the thin plate bend bending equation) of less than or equalto 1% of the Young's modulus of the article. In some such embodiments,the sintered article has a thickness of about 80 μm and a bend radius ofgreater than 0.03 m, the article exhibits a maximum in plane stress (theabsolute value of stress, as measured by the thin plate bend bendingequation) of less than or equal to 25% of the bend strength (measured by2-point bend strength) of the article; or the sintered article has athickness of about 40 μm and a bend radius of greater than 0.015 m, thearticle exhibits a maximum in plane stress (the absolute value ofstress, as measured by the thin plate bend bending equation) of lessthan or equal to 25% of the bend strength (measured by 2-point bendstrength) of the article; or the sintered article has a thickness ofabout 20 μm and a bend radius of greater than 0.0075 m, the articleexhibits a maximum in plane stress (the absolute value of stress, asmeasured by the thin plate bend bending equation) of less than or equalto 25% of the bend strength (measured by 2-point bend strength) of thearticle. In some such embodiments, a portion of the sintered articlethat is flattenable comprises a length of about 10 cm. In some suchembodiments, one or both the first major surface and the second majorsurface of the sintered article has a flatness in the range of onehundred nanometers to fifty micrometers over a distance of onecentimeter along the length or the width. In some such embodiments, thesintered inorganic material comprises an interface having a majorinterface dimension of less than about 1 mm, wherein the interfacecomprises either one of or both a chemical inhomogeneity and crystalstructure inhomogeneity. In some such embodiments, the sinteredinorganic material comprises a ceramic material or a glass ceramicmaterial. In some such embodiments, the sintered inorganic materialcomprises any one of a piezoelectric material, a thermoelectricmaterial, a pyroelectric material, a variable resistance material, or anoptoelectric material. In some such embodiments, the sintered inorganicmaterial comprises one of zirconia, alumina, yttria stabilized zirconia(YSZ), spinel, garnet, lithium lanthanum zirconium oxide (LLZO),cordierite, mullite, perovskite, pyrochlore, silicon carbide, siliconnitride, boron carbide, sodium bismuth titanate, barium titanate,titanium diboride, silicon alumina nitride, aluminum oxynitride, or areactive cerammed glass-ceramic. In some such embodiments, the sinteredarticle comprises at least ten square centimeters of area along thelength that has a composition wherein at least one constituent of thecomposition varies by less than about 3 weight % across the area. Insome such embodiments, the sintered article comprises at least tensquare centimeters of area along the length that has a crystallinestructure with at least one phase having a weight percent that varies byless than about 5 percentage points, across the area. In some suchembodiments, the sintered article comprises at least ten squarecentimeters of area along the length that has a porosity varies by lessthan about 20%. In some such embodiments, the one or both the firstmajor surface and the second major surface of the sintered article has agranular profile comprising grains with a height in a range from 25 nmto 150 μm relative to recessed portions of the respective surface atboundaries between the grains. In some such embodiments, the one or boththe first major surface and the second major surface of the sinteredarticle has a flatness in the range of 100 nm to 50 μm over a distanceof one centimeter along the length or the width. In some suchembodiments, the one of or both the first major surface and the secondmajor surface of the sintered article comprises have at least ten squarecentimeters of area having fewer than one hundred surface defects fromadhesion or abrasion with a dimension greater than 5 μm. In some suchembodiments, the other of the first major surface and the second majorsurface of the sintered article comprises surface defects from adhesionor abrasions with a dimension of greater than 5 μm, such as due tosliding along a surface of the furnace during sintering. In some suchembodiments, the substrate comprises an electrically conductive metal.In some such embodiments, the substrate comprises aluminum, copper, orcombinations thereof. In some such embodiments, the substrate comprisesa compliant polymer material. In some such embodiments, the substratecomprises a polyimide. In some such embodiments, the sintered articlejoined directly or indirectly to the substrate is rolled around a coreat least once, the core having a diameter of less than 60 cm. In somesuch embodiments, the package is further comprising an interlayer thatjoins the sintered article and the substrate, such as where theinterlayer has a thickness less than 40 μm and/or where the substratecomprises grooves that contact the interlayer. In some such embodiments,the package is further comprising a metal-based layer on at least aportion of one or both the first major surface and the second majorsurface of the sintered article, such as where the metal-based layercomprises copper, nickel, gold, silver, gold, brass, lead, tin, orcombinations thereof and/or where the metal-based layer and thesubstrate are joined to same major surface of the sintered article,and/or where the metal-based layer is joined to the sintered articlethrough an aperture in the substrate. In some such embodiments, thepackage is further comprising a semiconductor device electricallyconnected to the metal-based layer, such as where light that emanatesfrom an LED on the semiconductor device transmits through the bodythickness of the sintered article, and/or wherein the sintered articlehas a thermal conductivity greater than 8 W/m·K.

Additional aspects of the present disclosure relate to method of makingsome or all of the packages just described, the method comprising a stepof joining the substrate directly or indirectly to the first or secondmajor surface of the sintered article. In some such embodiments, thesubstrate comprises a compliant polymer material. In some suchembodiments, the substrate comprises an electrically conductive metal.In some such embodiments, the method further comprises applying aprecursor interlayer to one or both of the substrate and the sinteredarticle, the precursor interlayer joins the substrate and the sinteredarticle. In some such embodiments, the method further comprisesthermally deactivating the temporary adhesive to separate the substratefrom the sintered article. In some such embodiments, the method furthercomprises bonding a metal-based layer on at least a portion of one orboth the first major surface and the second major surface of thesintered article, and the method may further comprise electricallyconnecting a semiconductor device to the metal-based layer.

Aspects of the present disclosure relate to a process for forming asintered tape material comprising steps of (1) moving a tape toward aheating station, the tape comprising grains of inorganic material, (2)coupling a first section of a threading material to a leading section ofthe tape, (3) pulling both the first section of threading material andthe leading section of the tape through the heating station by applyinga force to a second section of the threading material located outside ofthe heating station, and (4) heating at least a portion of the tapewithin the heating station to a temperature above 500 degrees C. suchthat the inorganic material of the tape is sintered as it moves throughthe heating station. In some such embodiments, the heating station hasan entrance and an exit, and the process is further comprising a step ofpositioning the threading material such that the threading materialextends through the heating station, that the first section of thethreading material is located upstream from the entrance and that asecond section of threading material is located downstream from theexit, where the coupling step occurs after the positioning step. In somesuch embodiments, the threading material is an elongate strip ofmaterial that is different from the inorganic material of tape, such aswhere the difference between the threading material and the inorganicmaterial of tape is at least one of a different material type anddifferent degree of sintering, and/or where the leading section of thetape overlaps the first section of the threading material such that alower surface of the tape contacts an upper surface of the threadingmaterial. In some such embodiments, the coupling step comprises bondingthe threading material to the tape via an adhesive material, such aswhere a coefficient of thermal expansion of the threading material iswithin plus or minus 50% of a coefficient of thermal expansion of theinorganic material of the tape and is within plus or minus 50% of acoefficient of thermal expansion of the adhesive material, and/or wherethe inorganic material of the tape is at least one of a polycrystallineceramic material and synthetic mineral, where the adhesive material is aceramic containing adhesive material, and where the threading materialis at least one of a sintered ceramic material and a metal material. Insome such embodiments, the step of moving the tape toward the heatingstation includes unwinding the tape from an input reel, where the secondsection of the threading material is coupled to an uptake reel, and theforce is generated by rotation of the uptake reel. In some suchembodiments, the process further comprises a step of continuing to movethe tape through a heating station following unwinding from the inputreel forming a length of sintered inorganic material of the tape; andanother step of winding the tape on an uptake reel following heating andsintering, such as where the tape is held in a substantially horizontalposition during heating, such as where the tape on the input reelfurther comprises an organic binder material supporting the grains ofinorganic material, and the process further comprises heating the tapeto a temperature between 200 degrees C. and 500 degrees C. to remove thebinder material before the step of heating the tape to a temperatureabove 500 degrees C.

Aspects of the present disclosure relate to a process for forming aspool of sintered tape material comprising steps of (1) unwinding a tapefrom an input reel, the tape comprising grains of inorganic material;(2) moving a threading material through a channel of a heating stationin a direction from an exit of the heating station toward an entrance ofthe heating station such that a first section of a threading materialextends out of the entrance of the heating station; (3) coupling thefirst section of the threading material to the tape; (4) coupling asecond section of the threading material to an uptake reel locateddownstream from the exit of the heating station; (5) rotating the uptakereel such that tension is applied to the threading material by theuptake reel which in turn is applied to the tape pulling the tapethrough the heating station; (6) heating at least a portion of the tapewithin the heating station to a temperature above 500 degrees C. suchthat the inorganic material of the tape is sintered as it moves throughthe heating station; and (7) winding the tape on an uptake reelfollowing heating and sintering. In some such embodiments, at least oneof: (i) the threading material and the inorganic material of tape aredifferent from each other and (ii) a degree of sintering of thethreading material is greater than a degree of sintering of theinorganic material of the tape on the input reel. In some suchembodiments, the leading section of the tape overlaps the first sectionof the threading material such that a lower surface of the tape contactsan upper surface of the threading material, and the coupling stepcomprises bonding the threading material to the tape via an adhesivematerial.

Aspects of the present technology relate to a roll to roll tapesintering system comprising (1) an input roll of a length of tapematerial comprising grains of inorganic material, the inorganic materialof the tape material on the input roll having a first porosity; (2) asintering station comprising: (2a) an entrance; (2b) an exit; (2c) achannel extending between the entrance and the exit; and (2d) a heaterheating the channel to a temperature greater than 500 degrees C., wherewherein the tape material extends from the input roll toward theentrance of the sintering station, where heat within the channel causessintering of the inorganic material of the tape material; (3) an uptakeroll winding the length of tape material following exit from thesintering station; and (4) a length of threading material extendingthrough the exit and out of the entrance of the sintering station,wherein a first end section of the threading material is coupled to aleading section of the tape material before the entrance of thesintering station and a second end section of the threading material iswrapped around the uptake roll such that tension applied to thethreading material by winding of the uptake roll is applied to the tapematerial. In some such embodiments, at least one of: (i) the threadingmaterial and the inorganic material of tape material are different fromeach other and (ii) a degree of sintering of the threading material isgreater than a degree of sintering of the inorganic material of the tapeon the input roll. In some such embodiments, the leading section of thetape material overlaps the first section of the threading material suchthat a lower surface of the tape material contacts an upper surface ofthe threading material, and the threading material is coupled to thetape material via a bond formed by an adhesive material, such as wherethe inorganic material is at least one of a polycrystalline ceramicmaterial and synthetic mineral, where the adhesive material is a ceramicadhesive material, and where the threading material is at least one of asintered ceramic material and a metal material. In some suchembodiments, the exit, the entrance and the channel of the sinteringstation lie in a substantially horizontal plane, such that an angledefined between the exit and the entrance relative to a horizontal planeis less than 10 degrees.

Aspects of the present disclosure relate to a process for forming asintered tape material comprising steps of (1) unwinding a tape from aninput reel, the tape comprising grains of inorganic material, whereinthe tape on the input reel has an average thickness between 1 micron and1 millimeter; (2) moving the unwound length of tape through a heatingstation along a path having a first curved section such that the tape isbent through a radius of curvature of 0.01 m to 13,000 m; (3) heatingthe tape within the heating station to a temperature above 500 degreesC. while the unwound length of tape is bent through the radius ofcurvature, wherein the inorganic material of the tape is sintered as itmoves through the heating station; and (4) winding the tape on a take-upreel following heating and sintering. In contemplated embodiments, sucha process may be broader, and may not include the unwinding and/or thewinding steps. In some such embodiments, the heating station includes alower surface and an upper surface defining a channel extending betweenan entrance and an exit of the heating station, where the lower surfaceincludes a convex curved surface extending in a longitudinal directionbetween the entrance and the exit, wherein the convex curved surfacedefines the first curved section of the path. In some such embodiments,the upper surface includes a concave curved surface matching the convexcurved surface of the lower surface such that a height of the channelremains constant along at least a portion of a length of the channel. Insome such embodiments, the convex curved surface is an upper surface ofa gas bearing, and the gas bearing delivers pressurized gas to thechannel to support the tape above the convex curved surface as the tapemoves through the heating station. In some such embodiments, the convexcurved surface is continuous curved surface the extends an entirelongitudinal length between the entrance and the exit, wherein a maximumrise of the convex curved surface is between 1 mm and 10 cm. In somesuch embodiments, the path through the heating station has a secondcurved section having a radius of curvature of 0.01 m to 13,000 m, wherethe tape is heated within the heating station to a temperature above 500degrees C. while the unwound length of tape is bent through the radiusof curvature of the second curved section, such as where the tape isheated to a first temperature when the tape traverses the first curvedsection and is heated to a second temperature, different from the firsttemperature, when the tape traverses the second curved section. In somesuch embodiments, the first curved section of the path is defined by afree loop segment in which the tape hangs under the force of gravitybetween a pair of supports to form the radius of curvature in the tape.In some such embodiments, the heating station has a convex curvedsurface located therein defining the first curved section of the path,and the process further comprises a step of applying tension to the tapesuch that the tape bends into conformity with the convex curved surface,such as where the convex curved surface is an outer surface of at leastone of a mandrel and a roller. In some such embodiments, the tape ismoved through the heating station at a speed of between 1 inch and 100inches of tape length per minute. In some such embodiments, tension isapplied to the tape in a longitudinal direction, where the tape has awidth and the tension is at least 0.1 gram-force per linear inch ofwidth of the tape. In some such embodiments, the inorganic material ofthe tape is at least one of a polycrystalline ceramic material andsynthetic mineral.

Aspects of the present disclosure relate to a process for forming asintered tape material comprising steps of (1) moving a contiguouslength of tape through a heating station such that a first portion ofthe contiguous length of tape is located upstream from an entrance ofthe heating station, a second portion of the contiguous length of tapeis located downstream from an exit of the heating station, and a thirdportion of the contiguous length of tape is located between the firstportion and the second portion, the contiguous length of tape comprisinggrains of inorganic material, (2) heating the third portion of thecontiguous length of tape within the heating station to a temperatureabove 500 degrees C. such that the inorganic material is sintered withinthe heating station, and (3) bending the third portion of the contiguouslength of tape to a radius of curvature of 0.01 m to 13,000 m while atthe temperature above 500 degrees C. within the heating station. In atleast some such embodiments, the bending includes applying alongitudinally directed force to the contiguous length of tape such thatthird portion bends around a curved surface located within the heatingstation. In at least some embodiments, the contiguous length of tape isunrolled from an input reel, the contiguous length of tape is movedcontinuously and sequentially through the heating station such thatentire contiguous length of the tape experiences bending to the radiusof curvature of 0.01 m to 13,000 m while moving through the heatingstation, and where the contiguous length of tape is rolled onto atake-up reel following bending and heating.

Aspects of the present disclosure relate to a roll-to-roll tapesintering system comprising (1) an input roll of a length of tapematerial comprising grains of inorganic material, the inorganic materialof the tape material on the input roll having a first porosity; (2) asintering station comprising: (2a) an entrance; (2b) an exit; (2c) achannel extending between the entrance and the exit; (2d) a heaterheating the channel to a temperature greater than 500 degrees C.; wherethe tape material passes from the input roll, into the entrance of thesintering station, through the channel of the sintering station and outof the exit of the sintering station and the heat within the channelcauses sintering of the inorganic material of the tape material; (3) abending system located within the sintering station inducing a radius ofcurvature along a longitudinal axis of the tape material as the tapematerial passes through the heating station, wherein the radius ofcurvature is 0.01 m to 13,000 m; and (4) a take-up roll winding thelength of tape material following exit from the sintering station; wherethe inorganic material of the tape material on the take-up roll has asecond porosity that is less than the first porosity. In some suchembodiments, the exit and the entrance lie in a substantially horizontalplane such that an angle defined between the exit and the entrancerelative to a horizontal plane is less than 10 degrees, wherein thebending system includes a convex curved surface located along a pathbetween the entrance and the exit, wherein the tape is bent around theconvex curved surface as the tape moves through the heating station,wherein the convex curved surface defines the radius of curvature and iscurved around an axis parallel to a width axis of the tape material. Insome such embodiments, the convex curved surface is an outer surface ofat least one of a mandrel and a roller and/or the convex curved surfaceis a lower surface of the sintering station that defines the channel ofthe sintering station, such as where the convex curved surface forms acontinuous curve that extends the entire length of the channel from theentrance to the exit of the sintering station. In some such embodiments,the convex curved surface is an upper surface of a gas bearing thatdelivers gas to the channel supporting the tape within the channelwithout contacting the convex curved surface. In other such embodiments,the bending system includes a pair of support structures located withthe sintering station, wherein the support structures are spaced fromeach other forming a gap and the tape sags downward due to gravitybetween the support structures to form the radius of curvature.

Aspects of the present disclosure relate to a roll-to-roll tapesintering system comprising (1) an input roll of a length of tapematerial comprising grains of inorganic material, the inorganic materialof the tape material on the input roll having a first porosity; (2) asintering station comprising: (2a) an entrance; (2b) an exit; (2c) achannel extending between the entrance and the exit having alongitudinal length, L, wherein a lower surface of the channel isdefined by a continuously curved surface extending the longitudinallength L and having a radius of curvature, R, and a maximum rise, H;wherein R=H+(L{circumflex over ( )}2)/H; wherein 0.1 mm<H<100 mm, and0.1 m<L2<100 m; (3) a heater heating the channel to a temperaturegreater than 500 degrees C.; wherein the tape material passes from theinput roll, into the entrance of the sintering station, through thechannel of the sintering station and out of the exit of the sinteringstation and the heat within the channel causes sintering of theinorganic material of the tape material; and (4) a take-up roll windingthe length of tape material following exit from the sintering station,wherein the inorganic material of the tape material on the take-up rollhas a second porosity that is less than the first porosity.

Some aspects of the present disclosure relate to a tape separationsystem for sintering preparation by separating parts of the tape fromone another, as disclosed above and discussed with regard to FIGS. 3, 4,6, 8 for example. More specifically, the tape separation system includesa source of tape material (e.g., pre-made roll, pre-made long strip,in-line green tape manufacturing) comprising a green tape and a carrierweb (e.g., a polymeric substrate) supporting the green tape. The greentape comprising grains of inorganic material in a binder (e.g., organicbinder as disclosed above, and may further include inorganic binder).The tape separation system further includes a peeler (see FIG. 8) fordirecting the carrier web in a rewind direction and directing the greentape in a downstream processing direction that differs from the rewinddirection, such as by angle C in FIG. 8; and a vacuum drum positionedand configured to receive the tape material from the source and conveythe tape material to the peeler. The vacuum drum comprises holes forapplying suction to the carrier web to facilitate tensioning the carrierweb. For example, suction of the vacuum drum applies attractive force tothe tape beyond the forces of gravity and friction. In alternativeembodiments, other sources of attractive force may be used, such asmagnetic forces acting on a magnetic carrier web, electrostatic forces,etc., where the vacuum drum may be more broadly characterized as anattractive drum. According to an exemplary embodiment, tension, in forceper cross-sectional area, in the carrier web is greater than tension inthe green tape as the tape material is conveyed from the vacuum drum tothe peeler, thereby mitigating deformation of the green tape duringseparation of the green tape from the carrier web. The carrier web bearsthe brunt of force used to move and control the tape. Similarly thepeeler with the removal of carrier web acts to protect the shape of thegreen tape, which in turn facilitates the particularly high qualitysintered article in terms of geometric consistency.

Other aspects of the present disclosure relate to a system forprocessing tape for sintering preparation, as shown and discussed withregard to FIGS. 9, 10, and 12 for example. The system includes a tapecomprising a green portion of the tape, the green portion having grainsof an inorganic material in an organic binder; and a binder burnoutstation comprising an active heater. The tape advances through thebinder burnout station such that the binder burnout station receives thegreen portion of the tape and chars or burns the organic binder as thegreen portion of the tape interfaces with heat from the heater, therebyforming a second portion of the tape prepared for sintering theinorganic material of the tape. In some embodiments, at an instant, thetape simultaneously extends to, through, and from the binder burnoutstation such that, at the instant, the tape includes the green portioncontinuously connected to the second portion, such as where the binderburnout station chars or burns at least most of the organic binder, interms of weight, from the green portion of the tape withoutsubstantially sintering the grains of the inorganic material. Such asystem may be particularly surprising to those of skill in the artbecause of perceived weakness of the tape with the organic binderremoved or charred, and with associated changes in dimensions of thetape during such processing. In some embodiments, system for processingtape for sintering preparation further includes an ultra-low tensiondancer that includes light-weight, low-inertia rollers to redirect thetape without exerting significant tension such that tension in thesecond portion of the tape is less than 500 grams-force per mm² of crosssection, thereby reducing chances of fracture of the second portion ofthe tape and facilitating long continuous lengths of the tape forsintering. In some embodiments, system for processing tape for sinteringpreparation blows and/or draws gas over the tape as the tape advancesthrough the binder burnout station, and the binder burnout station heatsthe tape above a temperature at which the organic binder would ignitewithout the gas blown and/or drawn over the tape, whereby the organicbinder chars or burns but the tape does not catch fire.

Additional aspects of the present disclosure relate to a manufacturingline comprising the above system for processing tape, where the binderburnout station is a first station and the manufacturing line furthercomprises a second station spaced apart from the first station. Thesecond station may be spaced apart from the first station as shown inFIG. 12, and/or there may be a common housing and separation may be dueto an intermediate ventilation system that controls air flow relative tothe two stations for example. The second station at least partiallysinters the inorganic material of the second portion of the tape to forma third portion of the tape, where, at an instant, the tape includes thegreen portion continuously connected to the third portion by way of thesecond portion. In some embodiments, the third portion of the tape issubstantially more bendable than the second portion such that a minimumbend radius without fracture of the third portion is less than half thatof the second portion, and the green portion is substantially morebendable than the second portion such that a minimum bend radius withoutfracture of the green portion is less than half that of the secondportion. In other embodiments, the tape or other article may notcomprise three different such portions, such as if only shorter lengthsof articles were processed using the sintering system. The manufacturingline may further include the tape separation system described above,such as with the peeler and vacuum drum.

Some aspects of the present disclosure relate to a sintering systemcomprising a tape material comprising grains of inorganic material and asintering station, such as discussed above with regard to FIG. 3 forexample. The sintering station includes an entrance, an exit, and achannel extending between the entrance and the exit. At an instant, thetape material extends into the entrance of the sintering station,through the channel, and out of the exit. Heat within the channelsinters the inorganic material such that the inorganic material has afirst porosity at the entrance and a second porosity at the exit that isless than the first porosity, such as at least 10% less by volume.Further, the wherein the tape material is positively tensioned as thetape material passes through the channel of the sintering station,thereby mitigating warpage, such as by tension applied via thelow-tension dancer, by reel winding/unwinding, directional air bearings,variation in roller speed, or other components of the system topositively apply tension to the tape material beyond gravitational andfrictional forces. In some embodiments, the tape material moves throughthe sintering station at a speed of at least 1 inch per minute, such asat least 10, at least 20, at least 40 inches per minute. For discretearticles, as opposed to long tapes as disclosed herein, the articles maystop or dwell within the sintering station, or may move differentspeeds. In some embodiments, the channel of the sintering station isheated by at least two independently controlled heating elements, wherethe heating elements generate a temperature profile where the channelincreases in temperature along the length of the channel in a directionfrom the entrance toward the exit of the sintering station, and where asintering temperature in the channel exceeds 800° C. (see, e.g., FIG. 19and related discussion above). In some embodiments, the sintering systemfurther includes a curved surface located along the channel of thesintering station (see, e.g., FIG. 58 and related discussion above),where the tape material bends relative to a widthwise axis of the tapematerial around the curved surface as the tape material moves throughthe sintering station, thereby influencing shape of the tape material,such as flattening the tape material and/or preventing bulges or otherdistortions (see, e.g., FIG. 1). In some embodiments, the exit and theentrance of the sintering station lie in a substantially horizontalplane, such that an angle defined between the exit and the entrance ofthe sintering station relative to a horizontal plane is less than 10degrees, thereby at least in part controlling flow of gases relative tothe channel. Applicants have found that, alternatively or in additionthereto, flow of gasses may be controlled by vents and fans and/or byconfining the tape in a narrow space. For example, in some suchembodiments, the sintering station further comprises an upward facingchannel surface defining a lower surface of the channel, and a downwardfacing channel surface defining an upper surface of the channel, wherethe downward facing channel surface is positioned close to an uppersurface of the tape material such that a gap between the upper surfaceof the tape material and the downward facing channel surface is lessthan 0.5 inches, thereby at least in part controlling flow of gases inthe channel. The tape material may be particularly wide, long, and thin,having a width greater than 5 millimeters, a length greater than 30centimeters, and a thickness between 3 micrometers and 1 millimeter, andthe inorganic material of the tape may be at least one of apolycrystalline ceramic material and synthetic mineral. In otherembodiments, the tape or other article may be narrower, shorter, and/orthicker, but sintering may not be efficient in terms of sinteringtime/energy cost, the tape may not roll and/or flatten as disclosedabove, etc.

Other aspects of the present disclosure relate to a process formanufacturing ceramic tape, the process comprising a step of sinteringtape comprising polycrystalline ceramic to a porosity of thepolycrystalline ceramic of less than 20% by volume, by exposingparticles of the polycrystalline ceramic to a heat source to induce thesintering between the particles. The tape is particularly thin such thata thickness of the tape is less than 500 μm, thereby facilitating rapidsintering via heat penetration. Further, the tape is at least 5 mm wideand at least 300 cm long. In some embodiments, the process furtherincludes a step of positively lengthwise tensioning the tape during thesintering. In some such embodiments, the process further includes a stepof moving the tape toward and then away from the heat source during thesintering, such as through the channel of the sintering station. In someembodiments, the amount of time of the sintering is particularly short,that being less than two hours in aggregate for any particular portionof the tape, thereby helping to maintain small grain size in the ceramictape, improving strength, reducing porosity, saving energy; for example,in some such embodiments, the time in aggregate of the sintering is lessthan one hour, such as compared to 20 hour for conventional batchsintering, and density of the polycrystalline ceramic after thesintering is greater than 95% dense by volume and/or the tape comprisesclosed pores after the sintering, no pin holes, few surface defects,geometric consistency, etc. In some embodiments, the tape comprises avolatile constituent that vaporizes during the sintering, such aslithium, where the volatile constituent is inorganic, and where the tapecomprises at least 1% by volume (e.g., at least 5%, at least 10%, and/orno more than 200%, such as no more than 100% by volume) more of thevolatile constituent prior to the sintering than after the sintering.While some of the volatile constituent may vaporize, Applicants believethat the present sintering technology is far more efficient thanconventional processes that use sealed crucibles that surround thesintering material in sand containing the volatile constituent toprevent release of the volatile constituent through high vaporpressures. Applicants have discovered that speed of sintering andgeometry of the article may be used to rapidly sinter such volatilematerials before too much of the volatile constituent escapes, and asource of excess volatile constituent can be added to green tape, asdisclosed above, to greatly improve properties of the resulting sinteredarticle, such as in terms of percentage of cubic crystals, small grainsize, less porosity, and greater ionic conductivity, hermeticity,strength, etc.

Still other aspects of the present disclosure relate to a tape (seeFIGS. 67A, 67B, 68, 69, for example, and related discussion; see alsoFIGS. 29 and 78 and related discussion above) or other article (e.g.,sheet) comprising a body comprising grains of inorganic material(ceramic, glass-ceramic, glass, metal) sintered to one another, such aswhere atoms in particles of the inorganic material diffuse acrossboundaries of the particles, fusing the particles together and creatingone solid piece, such as without fully melting the particles to liquidstate. With that said, embodiments include articles of amorphous ornearly amorphous material (e.g., FIG. 81). The body extending betweenfirst and second major surfaces, where the body has a thickness definedas distance between the first and second major surfaces, a width definedas a first dimension of the first major surface orthogonal to thethickness, and a length defined as a second dimension of the first majorsurface orthogonal to both the thickness and the width. The tape islong, having a length of about 300 cm or greater. The tape is thin,having a thickness in a range from about 3 μm to about 1 mm. The tape isparticularly wide, having a width of about 5 mm or greater. In otherembodiments, the tape or other article may have other dimensions, asdisclosed herein.

According to an exemplary embodiment, geometric consistency of the tapeis such that a difference in width of the tape, when measured atlocations lengthwise separated by a distance, such as 10 cm, 50 cm, 1 m,2 m, 10 m is less than a small amount, such as less than 200 μm, lessthan 100 μm, less than 50 μm, less than 10 μm; and/or a difference inthickness of the tape, when measured at locations lengthwise separatedby a distance, such as 10 cm, 50 cm, 1 m, 2 m, 10 m along a widthwisecenter of the tape (i.e. along the centerline extending the length ofthe tape), is less than a small amount, such as less than 50 μm, lessthan 20 μm, less than 10 μm, less than 5 μm, less than 3 μm, less than 1μm in some such embodiments. Laser trimming may help improve thegeometric consistency of the width of the tape. A layer (e.g., silica, amaterial with melting temperature above 500° C., above 800° C., above1000° C.), as shown in FIG. 103 overlaying the granular profile, mayimprove geometric consistency of the thickness and/or may be polished orprovide an alternative to polishing.

In some embodiments, the tape is flat or flattenable, as describedabove, such that a length of 10 cm of the tape pressed between parallelflat surfaces flattens to contact or to within 0.25 mm of contact withthe parallel flat surfaces, such as within 0.10 mm, such as within 0.05mm, such as within 0.03 mm, such as within 0.01 mm, without fracturing;and for example in some such embodiments, when flattened to within 0.05mm of contact with the parallel flat surfaces, the tape exhibits amaximum in plane stress of no more than 10% of the Young's modulusthereof, such as no more than 5% of the Young's modulus thereof, such asno more than 2% of the Young's modulus thereof, such as no more than 1%of the Young's modulus thereof, such no more than 0.5% of the Young'smodulus thereof. In some embodiments, the first and second majorsurfaces of the tape have a granular profile, such as where the grainsare ceramic (see FIG. 30B and related discussion, for example), andwhere at least some individual grains of the ceramic adjoin one anotherwith little to no intermediate amorphous material such that a thicknessof amorphous material between two adjoining grains is less than 50 nm,such as less than 10 nm, such as less than 5 nm, such as less than 2 nm,such as where crystal lattices of adjoining grains directly abut oneanother, as viewed by transition electron microscopy for example (see,e.g., FIGS. 73C, 74, 75 and related discussion).

In some embodiments, the body has less than 10% porosity by volumeand/or the body has closed pores, as shown in FIGS. 86B, 99B, 102 forexample. In some embodiments, the grains comprise lithium and/or anothervolatile constituent, and the body has ionic conductivity of greaterthan 5×10⁻⁵ S/cm, such as ionic conductivity of greater than 1×10⁻⁴S/cm, such as ionic conductivity of greater than 2×10⁻⁴ S/cm, such asionic conductivity of greater than 3×10⁻⁴ S/cm. In some embodiments, thebody has a particularly fine grain size (average), that being 15 μm orless, such as 10 μm or less, such as 5 μm or less, such as 2 μm or less,as measured by ASTM standard, as described above.

In some embodiments, the tape further includes anelectrically-conductive metal coupled to the first major surface of thebody, where in some such embodiments the body comprises a repeatingpattern of vias, and the electrically-conductive metal is arranged in arepeating pattern (see generally FIGS. 51 and 104). In some embodiments,the first and second major surfaces have a granular profile, the tapefurther includes a coating overlaying the granular profile of the firstmajor surface, and an outward facing surface of the coating is lessrough than the granular profile of the first surface, such as by atleast half (see, e.g., FIG. 103), where electrically-conductive metalcoupled to the first major surface is so coupled by way of bonding tothe outward facing surface of the coating. In some embodiments, theinorganic material has viscosity of 12.5 poise at a temperature greaterthan 900° C. (see, e.g., FIGS. 78 and 87).

Additional aspects of the present disclosure relate to a roll of thetape of any one of the above-described embodiments (see, e.g., FIGS.67A, 67B, 68, 69), wherein the tape is wrapped around and overlappingitself, such as in a spiral, bent to a radius of less than 1 m, such asless than 30 cm, such as less than 20 cm, such as less than 10 cm. Acore of the roll may be round in cross-section, or otherwise shaped.

Still other aspects of the present disclosure relate to a plurality ofsheets cut from tape of any one of the above-described embodiments (see,generally FIGS. 93, 104). According to an exemplary embodiment, thesheets have a common attribute with one another that is detectable todetermine that the sheets were manufactured using technology disclosedherein. For example, the common attribute may be at least one of: (a) acommonly positioned surface groove (b) a pattern of grooves in common;(c) a commonly present stress profile irregularity extending lengthwise;(d) a compositional incongruity in common, and (e) a common asymmetriccrystal phase distribution or common pattern in crystal concentration.

Some aspects of the present disclosure relate to a tape, comprising abody comprising ceramic grains sintered to one another, the bodyextending between first and second major surfaces, where the body has athickness defined as distance between the first and second majorsurfaces, a width defined as a first dimension of the first majorsurface orthogonal to the thickness, and a length defined as a seconddimension of the first major surface orthogonal to both the thicknessand the width; where the tape is thin, having a thickness in a rangefrom about 3 μm to about 1 mm; and where first and second major surfacesof the tape have a granular profile, and at least some individual grainsof the ceramic adjoin one another with little to no intermediateamorphous material such that a thickness of amorphous material betweentwo adjoining grains is less than 5 nm.

Some aspects of the present disclosure relate to a tape or othersintered article (e.g., fiber, tube, sheet, discs), comprising a bodycomprising ceramic grains sintered to one another, the body extendingbetween first and second major surfaces, where the body has a thicknessdefined as distance between the first and second major surfaces, a widthdefined as a first dimension of the first major surface orthogonal tothe thickness, and a length defined as a second dimension of the firstmajor surface orthogonal to both the thickness and the width; where thetape is thin, having a thickness in a range from about 3 μm to about 1mm; where first and second major surfaces of the tape have a granularprofile; and where the grains comprise lithium and the body has ionicconductivity greater than 5×10⁻⁵ S/cm or higher, as discussed above.Such an article may have a thickness of amorphous material between twoadjoining grains is less than 5 nm. In some embodiments, the article isat least 95% dense and has a grain size of less than 10 μm, such as atleast 97% dense and has a grain size of less than 5 μm. The article maybe co-fired with an anode and/or cathode material as part of a solidstate battery, for example.

Unless otherwise expressly stated, it is in no way intended that anymethod set forth herein be construed as requiring that its steps beperformed in a specific order. Accordingly, where a method claim doesnot actually recite an order to be followed by its steps or it is nototherwise specifically stated in the claims or descriptions that thesteps are to be limited to a specific order, it is in no way intendedthat any particular order be inferred. In addition, as used herein, thearticle “a” is intended to include one or more component or element, andis not intended to be construed as meaning only one. Similarly, piecesof equipment and process steps disclosed herein may be used withmaterials other than continuous tape. For example, while continuous tapemay be particularly efficient for roll-to-roll processing, Applicantshave demonstrated that a sled of zirconia or other refractory materialmay be used to draw discrete sheets of material or other articlesthrough equipment disclosed herein.

It will be apparent to those skilled in the art that variousmodifications and variations can be made without departing from thespirit or scope of the disclosed embodiments. Since modifications,combinations, sub-combinations and variations of the disclosedembodiments incorporating the spirit and substance of the embodimentsmay occur to persons skilled in the art, the disclosed embodimentsshould be construed to include everything within the scope of theappended claims and their equivalents.

What is claimed is:
 1. Electrolyte for a solid-state battery,comprising: a body comprising ceramic grains sintered to one another,wherein the grains comprise lithium, wherein thickness of the body,between first and second major surfaces thereof, is in a range from 3 μmto 1 mm; wherein the first and second major surfaces of the body have anunpolished granular profile such that the profile includes grainsprotruding outward from the respective major surface with a height of atleast 25 nm and no more than 150 μm relative to recessed portions of therespective major surface at boundaries between the respective grains;wherein the body has ionic conductivity greater than 5×10⁻⁵ S/cm.
 2. Theelectrolyte of claim 1, wherein fewer than 10 pin holes of across-sectional area of at least a square micrometer pass through thebody, per square millimeter of surface on average.
 3. The electrolyte ofclaim 1, wherein the granular profile includes grains with a height ofat least 150 nanometers relative to recessed portions of the respectivemajor surface at boundaries between the respective grains.
 4. Theelectrolyte of claim 3, wherein the height of the grains is no more than80 micrometers relative to recessed portions of the respective majorsurface at boundaries between the respective grains.
 5. The electrolyteof claim 1, wherein the body has a length of 5 m or greater.
 6. Theelectrolyte of claim 1, wherein the grains sintered to one another havean average grain size of 5 μm or less.